JBED Journal of Building Enclosure Design

Journal of Building Enclosure Design
An official publication of the National Institute of Building Sciences
Building Enclosure Technology and Environment Council (BETEC)
National Institute of Building Sciences: An Authoritative Source of Innovative Solutions for the Built Environment
Winter 2011
Winter 2011 1
Winter 2011 3
4 Journal of Building Enclosure Design
Published For:
The National Institute of Building
Sciences Building Enclosure Technology
and Environment Council
1090 Vermont Avenue, NW, Suite 700
Washington, DC 20005-4905
Phone: (202) 289-7800
Fax: (202) 289-1092
Henry L. Green, Hon. AIA
Chief operating Officer
Earle W. Kennett
Sustainable Retrofit of
Residential Roofs Using
Metal Roofing Panels,
Thin-Film Photovoltaic
Laminates and PCM
Heat Sink Technology
High Rise Igloos: The
Canadian Way, Eh
Isolation Sheets
Covering Self-Adhered
Membranes May
Enhance Drainage
Under Cement Plaster
Wall Claddings
Published By:
Matrix Group Publishing Inc.
Please return all undeliverable addresses to:
5190 Neil Road, Suite 430
Reno, NV 89502
Phone: (866) 999-1299
Fax: (866) 244-2544
President & CEO
Jack Andress
Thermal Efficiency of
Insulation and Effects of
Thermal Bridging in Concrete
and Masonry Systems
Stone Wool Insulation: A
Core Solution for Fire-Rated
Sandwich Wall Panels
Senior Publisher
Maurice P. LaBorde
Peter Schulz
Jessica Potter
Trish Bird
Shannon Savory
Karen Kornelsen
Lara Schroeder
Alexandra Walld
Finance/Accounting &
Shoshana Weinberg, Pat Andress,
Nathan Redekop
Director of Marketing &
Shoshana Weinberg
Sales Manager
Neil Gottfred
Matrix Group Publishing Inc.
Account Executives
Albert Brydges, Rick Kuzie, Miles
Meagher, Ken Percival, Benjamin Schutt,
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Declan O’Donovan, Marco Chiocchio,
Simara Mundo, Wayne Earle, Colleen Bell
Advertising Design
James Robinson
Layout & Design
Travis Bevan
©2011 Matrix Group Publishing Inc. All
rights reserved. Contents may not be
reproduced by any means, in whole or in
part, without the prior written permission
of the publisher. The opinions expressed
in JBED are not necessarily those of
Matrix Group Publishing Inc. or the
National Institute of Building Sciences/
Building Enclosure Technology and
Environment Council.
High Rise
Stone Wool
essage from Institute President
Henry L. Green
Message from BETEC Chairman
Wagdy Anis
Industry Updates:
BEC Corner
Buyer’s Guide
On the cover: For the construction
of this school in Norway, horizontal
stone wool insulated SWPs were used
to provide the school with the aesthetics desired as well as non-combustible
walls. If you look closely, you’ll notice
that the panels were also arranged to
look like a crossword puzzle. Photo
courtesy of OEM/Roxul Inc.
Winter 2011 5
Message from the National Institute of Building Sciences
The BEST3 Conference, themed High Performance Buildings
– Combining Field Experience with Innovation, will focus on
broadening the approach to high-performance buildings beyond green. Participants will learn about analyzing the building
enclosure in conjunction with other high-performance aspects
of a building, including heating, cooling, ventilation, acoustics,
fire protection, durability, productivity and sustainability.
Henry L. Green, Hon. AIA
With the success of BEST2 as our
guide, we are currently in the middle of
planning next year’s BEST3 Conference.
To be held April 2-4, 2012, in Atlanta,
Georgia, and hosted by the Building Enclosure Council-Atlanta, the conference
is gearing up to be an exciting event.
The BEST3 Conference, themed
High Performance Buildings – Combining Field Experience with Innovation,
will focus on broadening the approach
to high-performance buildings beyond
green. Participants will learn about analyzing the building enclosure in conjunction with other high-performance
aspects of a building, including heating, cooling, ventilation, acoustics, fire
protection, durability, productivity and
sustainability. Mark your calendars now.
On a related note, in our work to improve building enclosures, it is important that we look at how buildings react
in disasters. The building envelope plays
a crucial role in ensuring the sustainability of a structure. While providing
the necessary protection to assure the
operations of the indoor environment
and productivity of the designed building functions, it is also critical that the
enclosure design assist in the mitigation
of both manmade and natural disasters.
This topic was the focus of a summit the National Institute of Building
Sciences recently hosted for the Department of Homeland Security (DHS)
entitled, Stakeholders Summit on High
Performance Resilient Buildings and
Related Infrastructure – Designing for a
Resilient America. Building enclosures
were the subject of several presentations. Speakers discussed how building
envelopes assist in the mitigation of disasters, as well as how they contribute
to a structure’s sustainability.
The summit provided a forum for
representatives from federal agencies
and a number of public and private
sector organizations to gain an understanding of the issues concerning the
resilience of buildings and related infrastructure, discern possible strategies
to improve resiliency in buildings, and
develop a roadmap for the (DHS) and
other federal agencies to pursue in creating a resilient America.
With more than 70 participants, the
Resiliency Summit offered the opportunity to examine the culture of resilience
from varying perspectives. Summit
participants provided commentary on
issues of resilience for buildings and related infrastructure, including:
• Assessing the attributes needed for
• The integration and interdependence of resilience with security,
energy, environmental and other
building requirements;
• How various building practices influence and are influenced by the
need to capture resilience in our
built environment;
• What interactions and interdependencies are at the intersection
between natural hazards and sustainability; and
• Identifying the issues that intersect
between physical and cyber security.
The Institute is compiling the summit proceedings into a report. To
learn more and to sign up to receive
an emailed copy of the report when
it becomes available, visit www.nibs.
The summit is just one example of
how the Institute and its various councils and committees provide our members exposure to a cross-pollination
of ideas and themes. The results often
expand scientific development and improve industry technologies that benefit the built environment.
With the BEST3 Conference more
than a year away, this is a great time to
learn about other Institute programs
that will expand your expertise. Take a
free online course on the Whole Building Design Guide, check out the buildingSMART alliance’s latest projects
relating to building information modeling (BIM); find out about the High
Performance Building Council activities and more. The National Institute
of Building Sciences website (www.
nibs.org) is a great way to see what we
are doing. And while you’re on the site,
sign up for our electronic newsletter.
It will keep you up to date on all our
As always, I look forward to hearing
from you. If not before, I’ll see you in
Atlanta in 2012!
Henry L. Green, Hon. AIA
National Institute of Building Sciences
Winter 2011 7
Message from the Building Enclosure Technology and Environment Council
Wagdy Anis, FAIA, LEED-AP
Welcome to the Winter 2011
edition of JBED, the Journal of Building
Enclosure Design.
In December, the Building Enclosure
Technology and Environment Council
(BETEC) had its annual meeting in conjunction with The Whole Buildings XI
International Conference. What a great
conference that was! The Building Enclosure Council (BEC) chairs also had
their BEC National Meeting at that time.
Following are some interesting developments from the BETEC meeting.
As you may have noticed, the requirement for continuous insulation is
increasing in model codes. This is not
the end, either. It’s only the beginning.
Indeed, there is at least one federal
agency talking about mandating “Passiv Haus” insulation levels in its buildings. The more insulation that is added,
the more special challenges are placed
on supporting the cladding. This means
that building design and construction
needs to enter a new era of how to design and build these new and more
energy-efficient buildings. The old paradigms may not work any longer.
We need to ask some very important
questions. How is the cladding supported? What is the appropriate plane of the
window relative to the drainage plane?
Where are the air barrier and flashings?
How are windows structurally supported for dead load and wind loads,
especially with glazings that are heavier
in weight? How do we do this without
significant thermal bridges?
Although there are many innovators dealing with these issues already,
such as the Building America consulting teams, this knowledge is not mainstream, neither in the single-family
home industry, nor in commercial and
multi-family construction. BETEC has
decided that there needs to be an educational blitz that will bring solutions
for these challenges to the forefront, so
that a better understanding exists in the
design and construction communities.
As such, a symposium is being planned
by BETEC for the next Ecobuild conference, scheduled for December 2011. It
is being planned in collaboration with
the NAHB Research Center, which is a
subsidiary of the National Association
of Home Builders (NAHB).
Another significant event that took
place at the Buildings XI International
Conference was the U.S. Department of
Energy (DOE)’s road mapping session,
during which stakeholders reported
their ideas about prioritizing research.
BETEC reported its thoughts on this to
DOE, on behalf of more than 3,000 BEC
members. Ideas included:
• Quantify the energy losses at common thermal bridges. Make recommendations for the specific climate
zones when the expense of improved
thermal breaks are value-added.
• Slab-on-grade to exterior wall.
• Structured floor slab edges.
• Masonry shelf angles directly
bolted to structure or slab edge.
• Parapet conditions.
• Balconies.
• Zee-girts in cavity walls to support the rainscreen, spaced
versus continuous; galvanized
versus aluminum versus stainless
• Evaluate the performance of some
common heat air and moisture control materials.
• The durability of flashing materials, including the durability of the methods of joining and
• Long-term adhesion of peel-andstick membranes.
• Long-term performance of peeland-stick membrane joints, vertical and horizontal, with and
without term bars, shingled and
reverse shingled.
• Life span of sealants in a concealed condition such as inside of
a drained cavity wall system or the
inner line of a double sealant joint.
• Evaluate how to improve performance of curtain wall, spandrel and
shadow box conditions for various
climate conditions.
• Effect of metal backpans (thermally broken and not) on heat
transfer versus foil-faced mineral
wool alone.
• Double-glazing versus single for
• Effect of venting behind glazing,
potential thermal short-circuits,
build-up of dirt inside glass.
• Need for better framing members
from an energy-efficiency versus
structural needs.
• Impact of other high-performance parameters on energy-efficient design.
• Blast-resistance.
• High seismic zones.
BETEC’s October 26, 2010 symposium, “Why Green Buildings Cannot Be
Built Without Air Barrier Systems”, was a
great success. High-performance buildings were targeted and BETEC postulated that they cannot be built without air
barriers. BETEC also presented the fact
that LEED buildings are not airtight,
with variable energy-efficiency as a result, and showed its findings. The good
news is that the new version of LEED,
which is up for public review, proposes
to adopt ASHRAE 2010 mandatory requirements. This means that architects
will be required to design LEED buildings with air barriers. Attendees from
the U.S. Green Building Council were
also in attendance.
Finally, Canada’s National Building
Envelope Council (NBEC) is gearing
up for the 13th Canadian Conference
on Building Science and Technology.
It’s scheduled for May 10 to 13, 2011,
in Winnipeg, Manitoba. Also, the BEST
3 planning committee is actively working towards their 2012 conference in Atlanta, Georgia. I hope to see you at both!
Wagdy Anis, FAIA, LEED-AP
Chairman, BETEC Board
Chairman, JBED Editorial Board
Principal, Wiss Janney Elstner
Winter 2011 9
Sustainable Retrofit of Residential Roofs
Using Metal Roofing Panels, Thin-Film Photovoltaic
Laminates and PCM Heat Sink Technology
By Jan Kosny, Kaushik Biswas, William Miller, Phillip Childs and Scott Kriner
During 2009-2010, research teams representing the
Metal Construction Association, the largest North American trade
association representing metal building manufacturers, builders
and material suppliers; CertainTeed, one of the largest U.S. manufacturers of thermal insulation and building envelope materials;
Unisolar, the largest U.S. producer of amorphous silicone photovoltaic (PV) laminates; Phase Change Energy, a manufacturer of
bio-based phase change materials (PCMs); Oak Ridge National
Laboratory (ORNL); and the Fraunhofer Center for Sustainable
Energy Systems (CSE), which joined the team in 2010, analyzed
three experimental attics utilizing different roof retrofit strategies. The attics were located in the climatic conditions of east
The main goal of this project was the experimental evaluation
of PV-PCM roofs, a newly-developed sustainable re-roofing technology that consists of metal panels integrated with amorphous
silicone PV laminates and PCM heat sink. Collected experimental
results indicate that PV-PCM roofs acted as a passive solar collector during the winter, with the PCM storing solar heat throughout
the day and increasing the overall attic air temperature at night.
This could reduce technology heating loads.
According to the National Association of Home Builders
(NAHB), asphalt shingles are the most common type of roofing
material used in the United States, both in new home construction and re-roofing, accounting for over 60 percent of the residential roofing market. Asphalt roofs generally last from 12 to 20 years
and then they are either replaced or old shingles are covered with
new ones. Re-roofing generates an estimated 6.8 million tons of
waste asphalt shingles each year, equivalent to nearly 3 percent
of municipal solid waste (www.smartgrowth.org/library/waste_
One of the biggest environmental drawbacks to re-roofing
is that old shingles require large disposal areas that pollute the
environment over time (Townsend et al., 2007; Sengoz and Topal, 2005). Recycling and processing waste asphalt shingles into
other materials, such as asphalt pavements (Decker, 2002; Sengoz and Topal, 2005), has been gaining momentum in recent
years. However, other practices need to be explored to further
conserve landfill space. The experimental re-roofing techniques
presented here are intended to be installed directly on top of the
existing asphalt shingles, precluding the need for recycling or
disposal to landfills.
During the summer of 2009, three test attics were built at
the ORNL Field Exposure Testing Facility in order to evaluate a
new sustainable method of re-roofing utilizing metal panels, PV
laminates and PCM heat sinks. The first test attic represented the
traditional retrofit, where the old roofing materials were totally
removed and replaced with a new cover (Figure 1). Next, the
project team constructed two additional test attics utilizing roofover-the-roof retrofit technologies.
Figure 1. Cleaning the old shingle roof.
In the first case, metal roofing panels were installed directly on
top of the existing roof shingles without removal of the old materials. The new metal roof, utilizing cool roof coating technology,
will be referred to in this paper as infrared-reflective roofs (IRR).
The two radiative properties that characterize cool roofs are solar reflectance and thermal emittance. A cool roof minimizes the
solar heat gain of a building by first reflecting a large part of the
incoming radiation and then by quickly emitting the absorbed
portion. As a result, during the summer months, cool roofs show
lower temperatures than traditional roofs of similar construction,
reducing overall building cooling energy loads.
In the second case, which will be referred to as PV-PCM, metal
roof panels with pre-installed amorphous silicone PV laminates
were mounted directly on top of the old shingles (Figure 2).
Figure 2. Installation of PCM cells topped with reflective foilfaced fiberglass and roofing panels.
In order to minimize the thermal stresses generated during
sunny days by the PV laminate, internal heat sinks with air ventilation channels were used. A bio-based phase change material
(PCM) of melting point 84.2°F (29°C) and total enthalpy between
180 and 190 Joules/gram was utilized for this roof assembly. Figure 3 shows the results of the differential scanning calorimeter
Winter 2011 11
Figure 3. Differential scanning calorimeter (DSC) test data.
(DSC) tests for this material. The PCM was macro-packaged in between two layers of heavy-duty plastic foil forming arrays of PCM
cells (Figure 2).
In PV laminates sunlight is converted into electricity and heat
simultaneously (Van Helden and Zondag, 2002). In building integrated applications, the relatively high solar absorption of amorphous silicone laminates can be utilized during the winter for
solar heating purposes with PCM providing heat storage capacity.
This could decrease heating loads in the southern U.S. because
roof temperatures in this region can easily exceed 86°F (30°C) during winter months (Miller and Kosny, 2007; Kosny et al., 2007). By
the same token, PV laminates may also increase building cooling
loads during summer. To lessen this effect, the PCM cells were
covered with a .78 inch (2 cm) thick layer of high-density fiberglass insulation that had a reflective surface on top. Moreover, air
channels were included between the PCM cells and above the fiberglass insulation to promote natural air ventilation over the roof
deck, which could help reduce the attic-generated cooling loads
(Figure 4).
Figure 5. Three test attics, from the left: shingle roof, IRR roof
and PV roof followed with the test diagram of the IRR test attic.
Figure 6. Roof surface temperatures recorded during two
sunny days of January 2010.
Initially, it was expected that the increased R-value of the PVPCM roof (due to the combined thermal resistance of the fiberglass
with reflective surface, PCM and two air cavities) would dominate
its energy performance during the winter because the PCM was
designed to work primarily during the summer and mid-season
months. However, the measured roof surface temperatures shown
in Figure 6 demonstrate that PCM, with a melting point of 84.2°F
(29°C) and installed just under the metal roof panel, can easily go
through phase transition during winter sunny days.
Figure 7 shows daily fluctuations of the attic floor heat fluxes
recorded during two sunny days in November 2009 and January
2010. Significant solar gains can be observed in cases of the con-
Figure 4. The location of the PCM heat sink directly on top of
the old roofing material with air channels between the PCM
cells and above the fiberglass insulation.
Winter Test results
The thermal performance of the three test attics were simultaneously monitored during four winter months between 2009 and
2010. Tests were continued during the summer of 2010.
The left-hand side of Figure 5 shows a photograph of three
test attics. The right-hand side contains a diagram showing the
locations of measure sensors and basic heat fluxes for the IRR test
attic. All three test attics had the same configurations of measure
Figure 6 shows roof temperature profiles for each of the tested assemblies. From the roof energy performance stand-point, internal attic air temperature and attic floor heat flow are the most
important performance control factors. The higher the average
attic air temperature during the winter time, the lower the attic
heat losses.
12 Journal of Building Enclosure Design
Figure 7. Attic floor heat flux profiles recorded during late fall
and winter sunny days.
ventional shingle and IRR attics during the day. However, during
the night these two assemblies showed about 50 to 80 percent
higher heat loss compared to the PV-PCM attic. This is due to the
combined effect of extra insulation and PCM latent heat released
during the night. The approximately three-hour lag time observed
in the PV-PCM attic is evidence that the phase change material
worked as intended. Figure 8 confirms these findings.
of the IRR and PV-PCM assemblies were higher than in the attic
covered with shingles by about 3.5°F and 8°F (2°C and 4°C), respectively (Figure 9).
Figure 8. Average weekly attic floor heat losses recorded
during the winter season 2009-2010.
Figure 9. Average weekly attic air temperatures recorded
during the winter season 2009-2010.
In the IRR and PV-PCM roofs, the new metal panels were installed directly on top of the existing structures; therefore, the old
shingles enhanced thermal as well as moisture protection. In addition, the materials added to the underside of the metal panels
(for example, fiberglass insulation, air cavities and PCM) provided
extra thermal insulation and heat capacity to the PV-PCM roof. As
a result, the IRR and PV-PCM roofs had average weekly attic heat
losses that were about 18 and 30 percent lower than those from
the conventional attic with shingles, respectively (Figure 8). Due
to the lower heat losses, the average weekly attic air temperatures
The first test attic represented the traditional way of roof retrofitting, where the old roofing materials are totally removed, disposed of and replaced with new roof shingles. The two other attics
utilized roof-over-the-roof technologies. In both cases, metal panels were installed directly over the existing roofs without a need for
removal of the old materials. In the case of the third test attic, roofintegrated PV laminate and PCM heat sink were utilized as well.
The test data demonstrated that roof-over-the-roof re-roofing
Continued on page 35
Winter 2011 13
High Rise Igloos: The Canadian Way, Eh
By Joe Lstiburek
Canadians do live in igloos.
However, unlike the Inuit snow block version, our more typical “igloos” are taller
than 10 stories and they are made out of
foam. Insulated concrete forms (ICFs) are
beginning to come into their own in many
locations, particularly in Ontario (Photograph 1 and 2). Think of large Lego
blocks made from polystyrene insulation
filled with concrete (Photograph 3).
The foam is a stay-in-place form for castin-place concrete¹ (Figure 1).
The “effective” thermal resistances
of these assemblies range from R-16 to
R-25, depending on the specific product
and the floor details. That is usually two
to four times the effective thermal performance of most typical assemblies.²
There is no fluffy stuff shoved into steel
stud thermal bridges and no exposed slab
edges—just continuous glorious thermal
insulation. It takes your breath away.
It gets better. Clip-on balconies,
French balconies, rail balconies (Figure
2) and other structural innovations have
seemingly banished the typical thermal
bridging associated with multi-story concrete frame apartment construction.³
Harley Davidson architecture is dead (see
“A Bridge Too Far”, ASHRAE Journal, October 2007).
When ICFs are used in apartment
construction with internal compartmentalization (Figure 3), distributed
ventilation systems (Figure 4) and distributed conditioning systems (Figure 5),
the energy performance is nothing short
of extraordinary (see “Multifamily Buildings” ASHRAE Journal, December 2005).
The only possible thing that can mess up
the performance is over-ventilation.4
With ICF construction service, raceways are routered into the interior layer
of foam to run wiring. A gypsum board
interior liner provides the interior finish.
Exterior claddings are typically directly
applied synthetic stuccos or manufactured stone veneers (Photograph 4
and 5).
The water control layer is typically the
rendering applied to the exterior face of
the ICF. Think of a mass wall with no water sensitive elements. Incidental leakage
through the exterior rendering is stored
and dissipated in the foam and concrete
layers of the remainder of the assembly. Drying happens in both directions.5
Claddings that do not require renderings
are attached to the exterior of the foam
blocks with furring strips. The back ventilation and back drainage of these types of
claddings limit the water load on the exterior face of the foam blocks, such that no
treatment of the exterior face of the foam
blocks is necessary. With respect to rain
penetration, the joints in the foam blocks,
can be ignored.
Like most systems, ICFs are not perfect—they come with their own set of “issues”. One annoying one is that you can’t
see the concrete. Huh? Think about it.
You can’t inspect the concrete for voids
the way we do with typical cast-in-place
concrete because you don’t strip away
the forms. The heads of building officials
exploded trying to deal with the problem. It was fun to watch for a while.
Then we fixed things. At first, ultrasonics were required at random points to check
for voids. It turned out that the easy answer is to measure the volume of concrete
placed. Because the foam blocks are accurately sized and spaced formwork, comparing the predicted volume of concrete
needed to the concrete actually placed can
catch large errors. There is already an infrastructure in place for projects of this scale,
which include counting trucks, how many
cubic yards are sent to the job, how many
are returned and if any is dumped on the
ground. Some small voids (for example,
hand-sized) are still possible but these
have little to no structural effect.
Another annoying issue is the water
management of “punched openings”,
such as windows. There are only two
kinds of windows in the world—those
that leak and those that will leak. So,
Photograph 2. Thermally broken
balconies. Clip on balconies where
exterior balcony corners are supported by
columns supported by the balcony below.
Photograph 1. A high rise ICF, 15 stories.
Photograph 3. Foam building blocks.
Stack ‘em up and fill ‘em with concrete.
Figure 1. ICF Section. It’s a beautiful thing
to see all of that continuous insulation.
Winter 2011 15
Figure 3. Unit air tightness. Each unit is
isolated from adjacent units and from
the exterior by an air barrier system of a
minimum recommended resistance or
air permeance of 2.00 L/(s.m2) @ 75 Pa.
Figure 2. All of these approaches allow for continuous insulation behind the balcony slabs.
Figure 4. Distributed ventilation. Individual unit ventilation is provided across
exterior walls. Outside air is supplied to unit air handlers. A motorized damper is
installed in line with an outside air duct connected to return side of air handler. A
programmable thermostat controls the damper and air handler.
16 Journal of Building Enclosure Design
what to do? Easy; wrap the water control layer around the window opening,
creating an under window “gutter” (Figure 6). In most cases the water control
layer is a synthetic stucco rendering. It
can also be a “liquid applied flashing
system” that is then integrated with the
exterior layer on the ICFs. As mentioned
earlier, with back-ventilated and backdrained exterior claddings attached to
the ICFs with furring strips, no additional water management on the exterior face of the foam blocks is necessary.
However, this does not apply to the
punched openings in such assemblies.
The punched openings need to be lined
with a liquid-applied flashing system to
get rainwater out to the exterior face of
the foam ICFs. Punched openings in all
ICF assemblies, regardless of the cladding system, need to be lined.
Now it’s time for the ultimate annoying issue. Hypothetically speaking, say
you are a frustrated building scientist and
you are entertaining the thought of actually throwing a Molotov cocktail. How
does an ICF or EIFS building fare when
it comes to intentional burning? It appears that the gypsum board inside and
a non-combustible cladding/coating outside should offer sufficient protection.
This is certainly the case if you believe all
of the fire testing that has been done on
the assemblies. Certainly the added airtightness helps suppress fire spread (but
makes flashover worse). At the end of the
day, what can I say? Adding all this foam
on the outside of buildings sure makes
some folks nervous; not me, but some
folks who have grey hair (and you know
what I think about grey hair).6
Photograph 4. Synthetic stucco
rendering. Complex aesthetics are
possible and typical.
Figure 5. Distributed conditioning.
Individual unit exterior compressors
are located on rooftops or in drywells
(“pit” with screen). This allows
individual billing.
Photograph 5. Manufactured stone
veneer. Wire mesh set in a cementitious
rendering provides the base for an
adhered direct applied stone veneer.
Figure 6. Punched openings.
1. Notice I do not use the term “poured concrete”. You do
not “pour” concrete. You place concrete and you cast concrete…you never pour it. “Pouring” it implies too much
water. The best concretes have so little water in them you
can’t get them out of the truck. In fact, you should have to
use a super plasticizer to get them out of the truck. The
lower the water-to-cement ratio, the better. You should
never, ever have a water-to-cement ratio above 0.5, as that
is the “magic” number below which “bleed water” does not
appear. You want a “dry concrete” that you “wet cure” for
a long time. The Romans figured this out over 2,000 years
ago. I can hear the Roman engineering concrete mantra in
my brain right now: “Claudius Maximus, remember what
that old engineering Centurion said—you want to place
your concrete as dry as possible and then keep it as wet
as possible for as long as possible…” (spoken in Latin of
2. I will let all of you in on a little secret because architects
don’t read footnotes. The real deal on the extraordinary
thermal performance of ICF buildings is that architects
can’t put in too many windows. They are limited by the
structural constraints of ICFs to no more than a 30 percent
glazing ratio. More glass than that and ICFs can’t be used
to provide the structure—you have to go to traditional columns and beams. When I hear architects talk about the
“thermal mass” effects of ICFs, I try not to roll my eyes.
Whatever. If that is what you believe, knock yourself out.
You could get the same performance in a more conventional structure if you limited glass and provided continuous insulation over the exterior of the structure. If you use
ICFs you have no choice.
One of the things about ICFs that is
not annoying is the sound transmission
quality of the assemblies. When excellent windows are used (I mean, who uses
bad windows these days?), with interior compartmentalization, you can approach sound studio acoustics. Alas, that
can now be annoying because installing
noisy appliances and equipment in an
essentially soundproof unit is, ahem,
It’s like a soundproof padded cell that
allows one to rant and rave about the
failings of LEED without disturbing the
neighbors. Plus, the compartmentalization and individual unit ventilation allows you to have a cigarette afterwards
without compromising anyone’s air
quality except your own. Was it good for
you too?
Joseph Lstiburek, Ph.D., P.Eng.,
ASHRAE Fellow, is a principal of Building
Science Corporation. He is a building scientist who investigates building failures
and is internationally recognized as an
authority on moisture-related building
problems and indoor air quality.
3. Who would have thought that structural engineers
would “get it” and innovate-away thermal bridges at
balconies? I guess all we had to do was ask. Some of
the stuff is pretty amazing. Since nothing much typically happens in structural engineering, structural engineers apparently had time on their hands and used
their brains—I mean, when is the last time you heard of
a building falling down? We civil engineers thank them!
4. We can compensate for the over-ventilation by paying
the LEED carbon premium of approximately $2,000
per unit and install a heat recovery ventilator (HRV).
The folks that read footnotes are aware that in order
to get a LEED indoor environment “point” you need
to ventilate at a 30 percent higher rate than that specified by ASHRAE Standard 62. The energy wasted this
way can be recovered at cost of $2,000 per unit with an
HRV—hence the term LEED carbon premium.
5. Here is where I point out once again to not use impermeable linings such as vinyl wall-coverings or sheet
plastic vapor barriers. ICF assemblies do not require
interior vapor control layers (for example, vapor barriers or vapor retarders).
6. Bill Rose has a poignant riff on the issue: “The foam
solves your thermal problem, your moisture problem and your airflow problem. Now you have got a
fire problem.” Personally, I think you should be careful with your cladding choice. I think a cementitious
stucco rendering handles the fire question, along with
vertical/horizontal compartmentalization.
Winter 2011 17
Isolation Sheets Covering Self-Adhered Membranes
May Enhance Drainage Under Cement Plaster Wall Claddings
By Anthony J. Nicastro
The architecture, engineering
and construction (AEC) industry does
not fully understand the interaction between cement plaster, admixtures and
the polyethylene facers of self-adhered
membranes (SAM) and similar continuous membranes. Manufacturers of SAM,
commonly referred to as peel-and-sticks,
often recommend their products for use
in cement plaster wall systems. However,
cement plaster can bond to the polyethylene facers of SAM, which may adversely
affect drainage behind the cement plaster cladding.
We have also observed that cement
plaster can bond to building paper and
other water-resistive barrier (WRB) materials in a manner that can impede drainage. To mitigate the potential for bonding
between cement plaster and building
paper, industry members often include
two layers. The space between layers can
serve as a plane through which water can
drain. However, the industry has not yet
standardized the provision of an isolation
sheet when using polyethylene-faced
SAM or similar continuous membranes
as the water-resistive barrier (WRB).
The industry presumes SAM alone is a
sufficient water-resistive barrier. We performed limited scope, preliminary testing
of cement plaster samples to observe and
evaluate the potential bond characteristics of cement plaster and compared the
differences between assemblies using
building paper and SAM. In addition, we
explored the bonding effects of a common acrylic admixture, often used to reduce cracking in cement plaster.
Cement plaster assemblies rely on
the cement plaster cladding to deflect
bulk water and the concealed WRB to direct incidental water out of the cladding.
Typically, a two-ply system of building
paper creates a modified drainage plane
that prevents moisture from entering
the wall cavity and directs it to drainage
flashings. Essentially, the cement plaster
assembly functions like a compact cavity
18 Journal of Building Enclosure Design
wall where moisture that finds its way behind the cement plaster is managed and
directed out of the system by the WRB
and flashings.
To observe and evaluate the bonding characteristics of cement plaster to
WRBs, including building paper and SAM,
we performed testing on mock-ups that
simulate cement plaster wall assemblies.
The mock-ups also allowed us to speculate about the assembly’s ability to drain.
Hypothesis and variables
We hypothesized that a bonding condition would occur between Portland cement plaster and the polyethylene facers
of SAM materials and other WRBs such
as building paper. We also hypothesized
that cement plaster mixes with acrylic
admixture content would experience increased bonding.
Our testing protocol included two
independent variables: the type of WRB
and an acrylic admixture within the cement plaster mix. We varied the WRB between Grade D, 60-minute building paper
and a proprietary SAM with a polyethylene facer. In each mock-up, we either
included or excluded an acrylic admixture in proportions recommended by the
manufacturer. Our dependent variable—
what we observed at the end of each
experiment—was the degree of bond
between the cement plaster and WRB.
Our controls were duration of cure, curing conditions (for example, temperature
and humidity) and materials used to prepare all samples. The baseline standard
of comparison was a cement plaster mix
with no acrylic admixture applied over
building paper.
Scope and procedure
We limited the scope of our testing to
six mock-ups and therefore we did not
produce a statistically significant number
of tests. The objective of observing the
mock-ups was to reach preliminary conclusions regarding our hypothesis and
make recommendations for further testing. We constructed the mock-ups with
varying WRB and acrylic additive in the
cement plaster mix. Each mock-up consisted of a 1 ft by 1 ft (0.3 m by 0.3 m) piece
of plywood over which we mounted the
WRB undergoing observation (Figure 1).
Figure 1. All images courtesy of Simpson
Gumpertz & Heger Inc. (SGH).
Then we installed wood trim pieces
around the perimeter of the mock-up
to serve as a screed for the cement plaster. The trim pieces were back-screwed
through the plywood backing and a
loose-laid WRB. We then mixed the cement plaster and additives, in manufacturer-recommended proportions where
applicable, and we applied the plaster
over the WRB up to the perimeter screeds.
We used a prepackaged rapid set cement
plaster mix. After placing the cement
plaster, we stored and cured the mockups in a horizontal orientation according
to the cement plaster manufacturer’s instructions (Figure 2).
Figure 2.
To observe whether the cement plaster bonded to the underlying WRB, we
inverted the mock-up upside down and
removed the screed trim pieces. We then
removed the plywood backing while being
careful not to disturb the WRB and cement
plaster. With the backside of the WRB then
exposed, we peeled it back and observed
the bonding characteristics of the WRB to
the cement plaster. We also observed the
amount of cement plaster residue left behind on the surface of the WRB.
Our mock-ups consisted of the samples noted on the chart on page 22.
Qualitative observations
Our testing indicated no significant
difference between SAM and building
paper in terms of the amount of bonding
to cement plaster. We observed at least
some degree of bonding to the WRB in
all instances, supporting the idea that a
multi-ply WRB is the preferred installation method to ensure the wall system
will have an unblocked drainage plane.
We observed a greater degree of bonding between cement plaster and WRB in
samples that included an acrylic admixture. In all cases, there was a greater bond
and more plaster residue when the WRB
was building paper (Figure 3A and 3B).
While the amount of bonding and residue was greatest on building paper samples, SAM also took some force to remove
and cement plaster left some residue on
the polyethylene facer. The sample with
the greatest adhesion of cement plaster
was Number 3, which included building
paper and an acrylic admixture.
Anecdotal observations
On one project in the San Francisco
Bay area, we observed a horizontal, recessed window sill clad with cement
plaster. To evaluate the potential for the
sill to drain water effectively, a fellow
consultant carefully bored a hole in the
cement plaster to expose the sill SAM,
which was not covered with an isolation
sheet (Figure 4).
Figure 4. Water poured over SAM into a
cement plaster system did not drain for
over the course of an hour.
He then poured water in the hole
the full depth of the cement plaster and
monitored how long the water took to
drain. We watched a pool of standing
water in the hole remain stationary for
over an hour. The water was unable to
flow between the cement plaster and
SAM, which was the intended drainage
plane. The inability of water to effectively drain from the window sill at the
WRB/SAM surface under the cement
plaster was a factor that may have contributed to water entry into the building,
particularly at lath fasteners that missed
studs and material transitions.
Possible experimental errors
Throughout preliminary testing, we
encountered differences between our
Figure 3. (Left): Residue left behind on the building paper indicates the bonded
cement plaster blocked the drainage plane in the mock-up. (Right): Compared to a
sample lacking an acrylic admixture.
mock-ups and real-world application of
cement plaster, some variability in controls and other sources of possible errors.
We noted the following that may contribute to misleading results:
• Measurement of the bonded area on
the samples relied on careful but subjective visual observation of residue
and is therefore open to qualitative error. In addition, we assumed that cement plaster residue and the amount
of force required to separate the cement plaster and WRB are correlated.
• Workmanship of the cement plaster
application may be a variable, in that
varying pressure during plaster application may affect degree of bonding.
• The experiment evaluated a singular
cement plaster mix, acrylic admixture,
SAM and WRB that are typical industry materials. Other similar materials
may or may not behave the same way.
• Although we observed bonding in cement plaster systems, we have not
confirmed the exact nature of how
bonding affects drainage.
First and foremost, our mock-up results and in-field experience indicate
that a design that will allow water to drain
from the wall assembly is of paramount
importance. Proper design of a wall cladding assembly that can manage infiltrating water and direct it out of the building
will limit problems after construction.
While we did not test a statistically
significant number of samples, the testing supports our in-field observations of
cement plaster bonding to SAM that can
potentially minimize drainage of the wall
cladding system. Likewise, acrylic admixtures may inhibit the wall assembly’s
ability to drain.
Our mock-ups over building paper
show more bonding to the cement plaster
than the SAM mock-ups, but some bonding occurred in all samples, indicating the
importance of a multi-ply WRB system. In
two-ply building paper systems, if bonding between the cement plaster and the
outer layer of paper occurs, the system
can still function without loss of ability to drain. Water that passes behind the
outer layer of building paper, either at dry
laps or by permeating through, still has
Continued on page 22
Winter 2011 19
Continued from page 19
the ability to pass between the plies and
eventually travel out of the system. The
outer WRB layer keeps the inner WRB layer free from bonding to the cement plaster, allowing the system to drain.
In systems that utilize only SAM under
the cement plaster, bonding can impede
the flow of water at the membrane surface, increasing the potential for leaks if
any defects occur in materials or applications are proximate to the bonded area.
The fibrous nature of building paper may
explain why samples with building paper
required a greater amount of force to separate the cement plaster from the building paper. Results of our testing indicate
bonding between cement plaster and the
WRB is greatest in systems that have an
acrylic admixture, but all samples within
our testing scope possessed at least some
level of adhesion.
Neither WRB type nor admixture content can completely prevent adhesion.
For this reason, we conclude that wall
assemblies with SAM installed directly
under cement plaster should also have
an isolation sheet to prevent bond and to
maintain a drainage plane.
Traditional cement plaster systems
with two layers of building paper as the
WRB are suitable for many applications
but may not function as well as SAM
does from a waterproofing standpoint.
In many cases, high winds can drive water to the interior through fastener locations, dry laps and flaws in building paper
SAMs that consist of a polyethylene
carrier sheet and asphaltic-based adhesive
sheets may offer an enhanced potential to
seal around lath fastener penetrations and
fully-adhere at field laps, to resist water
Clearly, adding multiple layers of SAM
will not increase the assembly’s ability to
drain. However, the addition of an un-adhered isolation sheet, such as building paper, over the SAM will aid in draining the
wall. For buildings that have exposure to
wind-driven rain and have a low tolerance
for water entry, our preliminary testing
and in-field experience indicates the WRB
with the best water penetration resistance
for cement plaster walls is a SAM and isolation sheet of building paper. An isolation sheet of building paper will preserve
the drainage plane while including SAM in
the assembly will provide greater durability and water penetration resistance.
Applications and
recommendations for further
The results of our testing apply when
selecting materials for cement plaster
wall assemblies. When considering the
potential for leakage during the design
phase of a project, an isolation sheet is
a relatively inexpensive addition to a cement plaster assembly that only includes
SAM as the WRB.
While our preliminary testing suggests
bonding in cement plaster assemblies may
adversely affect drainage, more exact and
reproducible methods for measuring the
degree of bonding and its effect on drainage are necessary. A larger sample base
and more comprehensive material palette
would develop more broadly applicable
results. Finally, and most importantly, future experimentation could also include
a measure of drainage rates in mock-up
wall panels that include a broader range of
WRBs. Wall assemblies that vary WRB type
and cement plaster mix could be tested
with the objective of determining where
impeded drainage occurs.
We encourage industry members to
replicate and refine our preliminary experiments to shed light on the conditions
causing impeded drainage and their relationship to an increased incidence of
leakage. For further information regarding procedure and potential future applications not contained in this article,
contact the author.
Anthony J. Nicastro, P.E., is a senior engineer at national engineering firm Simpson Gumpertz & Heger Inc. (SGH). He is
experienced in the investigation, design
and construction contract administration
of building envelope components for major commercial, educational and residential buildings.
Nicastro has consulted with architects, contractors and building owners to
analyze design concepts, evaluate construction defects and develop repairs for
water intrusion issues. He can be reached at
Sample Log
Sample ID Acrylic Admixture
Building Paper
Building Paper
Building Paper
22 Journal of Building Enclosure Design
Adhesion to
Cement Plaster Observations
Minor resistance when facer pulled from plaster,
obvious plaster residue marks remaining on SAM.
Minor resistance when facer pulled from plaster,
obvious plaster residue remaining on SAM.
Strong resistance when building paper pulled
from plaster, heavy residue. Greater resistance
than in Samples 1 and 2.
Minor resistance when building paper pulled
from plaster, but greater resistance than Samples
1 and 2. Small amount of residue.
Minimal SAM to plaster adhesion, much less than
all other cases. SAM separated from cement plaster easily. Minimal cement plaster residue on SAM.
Minor resistance when building paper pulled
from plaster (less resistance than other tests with
building paper), but still greater resistance than
tests with SAM. Almost no residue.
Thermal Efficiency of Insulation
and Effects of Thermal Bridging
in Concrete and Masonry Systems
By Bryan Urban, Jan Kosny and Elisabeth Kossecka
Since many modern concrete and masonry
technologies are available today for residential and commercial buildings, it is important to know the impact of thermal
bridging and effective thermal insulation usage. Most often,
thermal bridges occur in building envelopes containing structural and insulating materials of significantly different thermal
conductivities. Current concrete and masonry technologies
sometimes contain relatively complex configurations of thermal insulation (Kosny et al. 1998).
For most concrete masonry units (CMUs) made of normalweight concrete of density between 120 and 140 lb/ft3 (1,9202,240 kg/m3), the thermal conductivity of concrete can be 20
times higher than that of foam insulation. Steel components
have thermal conductivities hundreds of times higher than
foam. For some shapes of insulation and structural components, hidden thermal shorts may cause considerable heat loss,
making it critical to optimize the sequence of layers, density of
concrete and configuration of mass and thermal insulation in
building envelopes.
Steel components have thermal conductivities
hundreds of times higher than foam. For some shapes
of insulation and structural components, hidden
thermal shorts may cause considerable heat loss,
making it critical to optimize the sequence of layers,
density of concrete and configuration of mass and
thermal insulation in building envelopes.
Six characteristic configurations of multilayer concrete
walls with one-dimensional heat transfer were evaluated in
this study to analyze the effect of the sequence of the material layers on overall energy effectiveness. The main goal of this
work was to evaluate the role of thermal bridging and thermal
performance of insulation used in concrete and masonry systems. The walls were composed of concrete and insulating
foam, each with identical R-values. The wall materials, however, were arranged in different ways. Whole building energy
analysis using DOE-2.1E was performed for six U.S. climatic
zones to compare annual heating and cooling loads for a single floor ranch house. In addition, to analyze thermal bridging
in complex CMUs, 2D and 3D finite difference modeling was
Steady-state and dynamic heat transfer modeling techniques have been in use for many years and advanced capabilities are available in numerous commercial software
packages. However, sometimes non-conventional analytical
and experimental methods must be developed to enhance
the understanding of the performance of massive building
envelope assemblies. During the second half of the twentieth
century, dynamic hot-box testing was introduced to experimentally determine the transient thermal characteristics of
complex massive systems (Kasuda 1969; Brown and Stephenson 1993; Kosny et al. 1998). Equivalent wall theory was introduced in order to enable numerical analysis of complex wall
assemblies using one-dimensional thermal models (Kossecka
and Kosny 1996; Kossecka 1999; Kosny et al. 2001).
Several energy codes, including CABO Model Energy
Code 1995, ASHRAE Standard 90.2 1993 and ICC IECC
2006, have already started to incorporate some energy performance data for massive wall configurations. Comparing
concrete and masonry systems of similar R-values shows that
some wall configurations are more thermally effective than
others, with performance depending on specific distributions
of mass and insulation inside these walls. This paper combines
the energy analysis of a small residential building, made of different configuration of concrete walls, with detailed R-value
simulations performed for several types of CMUs.
THE effect of Wall material layer positioning
on thermal loads
A series of annual heating and cooling energy simulations
were performed for a one-story residential building to analyze
the effect of the wall material configuration on whole building
heating and cooling loads. Six types of exterior wall structures,
presented as a to f in FIGURE 1, were simulated. The annual
whole building energy analysis program DOE-2.1E was used to
simulate dynamic heating and cooling loads. The ranch-type
house used in this modeling was the subject of previous energy efficiency studies (Huang at al. 1987; Kosny and Desjarlais
Figure 1. Annual cooling (top) and heating (bottom) loads
computed for six wall configurations (right) in six U.S.
Winter 2011 23
1994; Christian and Kosny 1996). It has approximately 1,540 ft2
(143 m2) of living area, 1,328 ft2 (123 m2) of exterior wall area, 8
windows and 2 doors (1 door is a glass slider and its impact is
included with the windows). The elevation wall area includes
1,146 ft2 (106 m2) of opaque (or overall) wall area, 154 ft2 (14.3
m2) of window area and 28 ft2 (2.6 m2) of door area.
The dynamic thermal response in multilayer concrete walls
depends on the arrangement of the wall materials. To demonstrate this effect, six examples of walls of the same resistance
and capacity but of different structure were examined. These six
sections are depicted in Figure 1. The main part of each wall
is composed of heavyweight concrete layers, totaling 6 inches
(152 mm) thick and insulation layers totaling 4 inches (102 mm)
thick. The interior layer is .5 inches (13 mm) thick gypsum plaster and the exterior layer is .75 inches (19 mm) thick stucco. Total wall thickness is L = 11.25 inches (286 mm). The total thermal
resistance for each wall is RT = 18.2 h·ft2·°F/Btu (3.2 m2·K/W),
the overall heat transfer coefficient is U = 0.052 Btu/h·ft2·°F
(0.311 W/m2·K), the total mass is M = 80 lb/ft2 (390 kg/m2) and
the wall thermal capacity is C = 16.1 Btu/ft2·°F (330 kJ/m2·K).
Material properties are given in Table 1.
For cooling loads, the highest percent differences in energy performance were observed for Denver, Colorado (over 60
percent), which has a very low cooling load. The next highest
percent differences (about 40 percent) were observed for Minneapolis, Minnesota, and Washington, D.C., two locations with
fairly low cooling loads. In the mixed climate of Atlanta, Georgia, the difference was about 25 percent. For other southern
U.S. climatic locations, the differences in cooling loads were
still between six and seven percent. This indicates that the sequence of massive and insulating wall materials may notably
affect whole building energy performance during the cooling
season only in mixed climates and northern U.S. locations. In
the southern-most U.S. locations, like Miami, Florida, or Phoenix, Arizona, the effect is moderate.
For heating loads, the differences were below five percent
in all locations that had a significant heating season. In Miami
and Phoenix, where heating loads are very low, the difference
was more than 30 percent. This suggests that the sequence of
mass and insulation wall materials has only a minor effect on
heating loads and will not notably affect whole building energy
performance during the heating season.
Table 1: Thermophysical properties of simulated wall materials
k Btu·in./
rho lb/ft3
Cp Btu/lb·ºF
10 (1.44)
0.20 (0.838)
0.25 (0.36)
1 (16)
0.29 (1.215)
Gypsum Board
1.11 (0.16)
50 (800)
0.26 (1.089)
SteadY-State Thermal Performance of
Concrete Masonry Units
A great variety of CMUs are available today. Some are simple
and consist of a single material (most likely concrete), while others have complex interlocking paths of structural and insulating
materials. In this paper, simple hollow block CMUs, which are
popular in the United States, are presented next to more advanced European multicore and interlocked CMUs. A series of
steady-state simulations was used to analyze the heat transfer in
the walls made of different types of CMUs. The finite difference
program, HEATING-7, developed by the Oak Ridge National Laboratory (ORNL), used in this study, was previously validated against
the hot-box test results for masonry and frame systems (Kosny
and Syed, 2004). As shown in Figure 2, the following six types of
12 inch (300 mm) thick CMUs were studied: solid block, two‑core
hollow block, cut‑web block, multicore block, solid block with
interlocking insulation insert, and solid block with serpentine
5 (0.72)
116 (1,856)
0.20 (0.838)
Whole building dynamic modeling results, shown in Figure 1, indicate that wall sections with massive layers located
towards the building interior—sections a, b and c—had the
best thermal performance for the climates considered. In general, the lowest annual loads occured for walls b and c, where
the thermal mass was concentrated primarily on the interior
side. In contrast, wall d, with its massive materials located towards the exterior side, generated the largest heating and cooling loads in every case. To show the effect, Table 2 summarizes
the difference between maximum and minimum loads among
the various wall configurations.
Table 2: Thermal load difference between min. and max. wall
Min Max
Min Max
Load Load
Load Load
Wall Walll Difference Wall Wall Difference
24 Journal of Building Enclosure Design
Figure 2. Simulated R-values of concrete masonry units with
different insulation configurations and the dependence on
the concrete R-value. Normal weight concrete is represented
by the two left-most shape markers.
insulation insert, (dimensions are given in Table 3). For each
shape of CMU, the R-value was computed as a function of thermal
resistivity of concrete used in the block production.
Table 3. Basic dimensions for analyzed 12 x 16 x 8 in. (300 x
400 x 200 mm) CMUs. Units are in. (mm)
Concrete Insulation Web Height
CMU Type
1.75 (44.5) 1.88 (47.8)
2.00 (51.0) 2.50 (63.5) 3.00 (76.0)
1.50 (38.0) 2.00 (51.0)
CMU With
2.50 (63.5) 1.70 (43.2)
CMU With
1. in.
2.00 (51.0)
and groove
Typically, wall R-value measurements are carried out by the
hot-box apparatus, such as the one described in ASTM C1363
(2005). The best-known historical hot-box test data for concrete and masonry walls can be found in Valore 1988, Van Geem
1986 and James 1990, and in the ORNL wall material database
(Kosny and Christian 1993). This paper presents computergenerated R-values of concrete and masonry wall technologies.
Simulated thermal resistances of these six shapes of CMUs are
depicted in Figure 3 as a function of concrete thermal resistivity. All cases were simulated for 12 inch (300 mm) thick CMUs. A
uniform thermal resistivity for all types of insulation inserts was
assumed as R-4 h·ft2·°F/Btu per inch (27.7 m·K/W). Thermal resistances for each CMU were estimated for five different values of concrete thermal resistivity: 0.19 (1.32), 0.28 (1.94), 0.40
(2.77), 0.59 (4.09), and 0.86 h·ft2·°F/Btu per inch (5.96 m·K/W).
These values approximately correspond, respectively, to the
following densities of concrete: 120 (1,920), 100 (1,600), 80
(1,280), 60 (980), and 40 lb/ft3 (640 kg/m3) (ASHRAE 1993).
Solid CMUs are normally produced with lightweight concretes. The R-value for a solid 12 inch (300 mm) thick CMU made
of lightweight concrete ranges from 5 to 10 h·ft2·°F/Btu (0.8-1.7
m2·K/W). As shown in Figure 2, the thermal performance of
two‑core units made of normal density concretes is very low. For
an uninsulated 12 inch (300 mm) thick unit, the R‑value is below
2 h·ft2·°F/Btu (0.35 m2·K/W). For insulated units made of normal
density concrete, the R‑value remains well below 3.5 h·ft2·°F/
Btu (0.62 m2·K/W). Since foam inserts are located in air cavities
portioned by highly conductive concrete webs, they cannot notably reduce negative effects of thermal shorts generated by the
transverse webs. If two-core units are made of lightweight concretes (not a common practice in the U.S.), their R-values may be
higher—about 4 h·ft2·°F/Btu (0.7 m2·K/W) for uninsulated CMUs
and 8 h·ft2·°F/Btu (1.4 m2·K/W) for insulated units.
Cut-web CMUs were designed to reduce heat losses caused
by transverse concrete webs in two-core units. Figure 2 shows
that the increase in thermal resistance caused by 40 percent concrete web reduction is minimal for units made of normal density
concretes: a comparison of R-value between insulated two-core
and cut-web units shows less than R-2 h·ft2·°F/Btu (0.35 m2·K/W)
difference. For the insulated 12 inch thick cut‑web unit made of
normal density concrete, the R‑value is below 5.4 h·ft2·°F/Btu
(0.95 m2·K/W). R‑values of the cut‑web units made of lightweight
concrete could exceed R-11 h·ft2·°F/Btu (1.94 m2·K/W).
As shown in Figure 2, for multicore units made of normal
density concretes, the R‑value of an uninsulated 12 inch (300
mm) thick unit is below 3.5 h·ft2·°F/Btu (0.62 m2·K/W) and for
an insulated unit it is about 6.8 h·ft2·°F/Btu (1.2 m2·K/W). It is
interesting that the R‑value of an uninsulated multicore unit
equals the R‑value of an insulated two‑core unit. For insulated
multicore units made of lightweight concrete, the R‑value could
exceed 19 h·ft2·°F/Btu (3.35 m2·K/W).
Solid blocks with interlocking insulation inserts are usually
made of lightweight concretes. As shown in Figure 3, for solid units with integral insulation inserts, the R‑value can exceed
16 h·ft2·°F/Btu (2.82 m2·K/W). For units with serpentine foam
insulation, the R-value can reach 20 h·ft2·°F/Btu (3.52 m2·K/W).
Note that all R-values presented account only for the blocks
themselves and do not account for mortar or grout. The mortar
joint area usually covers 4 to 10 percent of the total wall area. They
Figure 3. Simulated temperature profiles across the
uninsulated two-core CMU made of the low-density concrete.
Mortar joints are visible in areas of double concrete webs.
Figure 4. Mortar effect (CMU R-value reduction) in two-core
masonry units as a function of concrete thermal resistivity.
Winter 2011 25
may generate additional wall heat losses in masonry walls. Figure 3 shows a detailed computer model of three uninsulated
two-core CMUs connected together with mortar joints. The
areas where isotherms are not perpendicular to the direction of
bulk heat flow indicate intense thermal bridging. In the case of
two-core CMUs made of normal density concrete, the mortar
effect is negligible since thermal conductivities of mortar and
block concrete are almost the same. In the case of lightweight
concrete, as shown in Figure 3, the thermal effect of mortar is
more significant—the R‑value reduction can exceed 12 percent
for two‑core units (Figure 4).
Thermal Efficiency of Insulation in Concrete
masonry units
Foam insulation inserts are relatively expensive components
of CMUs, so it’s important to use this material effectively. There
are many masonry technologies offering several types of interstitial insulation inserts. Knowledge of the relative thermal efficiency (TE) of the insulation material used in CMUs can aid in
the thermal evaluations and design process. From another perspective, understanding how much insulation material has to be
used in the wall in order to effectively enhance its thermal performance can help to optimize concrete and masonry system costs.
When the nominal R-value of used insulation is compared to
the increase of wall R-value caused by this insulation, the actual
increase of the wall R-value is often significantly lower (Kosny
and Christian 1993; Kosny and Syed 2004). This can result in ineffective usage of the insulation material, as unintended thermal
bridges produce significant heat losses. The method of estimating TE value is based on R-value comparison of insulated (Ri)
and uninsulated (Ru) masonry units—each having the same face
area (Fu). The equivalent R-value of the insulation inserts (Re)
can be calculated for the layer of insulation material having the
same face surface area (Fu) as the CMU under consideration and
containing the same volume (Vins), which is used to insulate this
CMU. TE may be expressed by the following equation:
TE = (Ri-Ru)/Re x 100%
Ri=R‑value of insulated unit
Ru=R‑value of uninsulated unit
Re=equivalent R‑value of insulation material used
To calculate equivalent thickness de of thermal insulation
used in CMU, the insulation volume (Vins) is divided by the face
surface area (Fu) of the CMU. Equivalent thickness (de) can be expressed as follows:
Equivalent R‑value of the consumed insulation material Re is:
Re= ri x de
Where ri is the thermal resistivity of the insulation material.
The TE of the insulation material depends on the CMU shape
and concrete R-value, as shown in Figure 5. For all CMUs, the
insulation was more effective for lightweight concrete than for
normal weight concrete and in some cases, more than twice as
high. For most insulated blocks made of lightweight concrete,
except insulated multicore CMUs, the TE can reach 60 to 90
percent. Solid block CMUs with interlocking insulation had the
highest effectiveness, ranging from about 70 to 90 percent. The
serpentine-insulated solid block CMU and both insulated twocore CMUs showed medium effectiveness ranging from about
30 to 80 percent. Multicore CMU insulation was very ineffective,
ranging from only 20 to 60 percent. Filling many discontinuous
air cavities with insulation is less effective because the air cavities can provide a moderate base insulating value.
Simulated whole building thermal performance indicates
that the arrangement of massive and insulating layers within a
wall affects heating and cooling loads. Load variation among different wall configurations was greatest for cooling loads among
mixed and cooling dominated climates, and lowest for heating
loads in heating-dominated climates. Calculations indicate that
walls with massive layers towards the building interior (insulation towards the exterior) performed better than walls with massive layers towards the exterior (insulation towards the interior).
The use of lightweight concretes in production of CMUs is one
of the most effective ways to improve their thermal performance.
More complex CMUs made of lightweight concretes and containing interlocking or serpentine foam inserts may have R-values
ranging between 16 and 20 h·ft2·°F/Btu (2.82 and 3.52 m2·K/W).
The thermal efficiency of the insulation material in two‑core,
cut‑web and multicore units made of normal density concretes
varies only between 20 and 40 percent. This shows that 60 to 80
percent of the used thermal insulation does not generate any increase of the wall R‑value.
The results of this study show that an application of lightweight concretes in production of masonry units may help in
increasing insulation thermal efficiency, which can reach 90 percent for blocks made of lightweight concretes. n
Bryan Urban and Jan Kosny, PhD, are from the Fraunhofer
Center for Sustainable Energy Systems in Cambridge, Massachusetts. Elisabeth Kossecka, PhD, is from the Institute of Fundamental Technological Research, Polish Academy of Sciences, in
Warsaw, Poland.
Figure 5. Thermal efficiency of insulation in CMUs presented
as a function of concrete thermal resistivity.
26 Journal of Building Enclosure Design
A full list of references for this article is available upon request.
Please email ssavory@matrixgroupinc.net.
Stone Wool Insulation:
A Core Solution for Fire-Rated Sandwich Wall Panels
By Jim Miller
Despite core advantages and
unique benefits, stone wool insulation remains relatively unknown to the
North American sandwich wall panel
(SWP) industry. This is surprising when
you consider that stone wool insulation offers most, if not all, the key attributes required for SWP applications. It
is non-combustible, moisture resistant,
dimensionally stable, an excellent barrier to sound transmission, easy to assemble and install, has outstanding
thermal properties and is one of the
most environmentally sustainable insulation products available today.
While stone wool is recognized by
design professionals for use in commercial and industrial buildings for interior
walls, curtain walls, cavity walls and
low slope roof applications, it has yet to
gain any real traction with SWP manufacturers. One-, two- and three-hour
fire-rated wall systems can be achieved
with no difficulty using stone wool
insulated SWPs. Yet, expanded polystyrene (EPS), polyurethane foam
(PUR) and polyisocyanurate foam (PIR)
remain the preferred options.
The demand for environmentally
sustainable building products is growing, as is the need for improved fire
resistance in all buildings. With all its
unique properties, can an increase of
stone wool insulation in sandwich wall
panels be far behind?
The need for
non-combustible core SWP
The demand for stone wool in North
America lags behind Europe, primarily
because the need for SWP with a noncombustible core in Europe is substantially different than it is in North
European demand accelerated significantly in the 1990s as a result of the
number of fires in the United Kingdom
(UK) that involved SWP with combustible core insulation. Total fire losses in
the UK food processing industry, where
SWP with combustible insulation was
used, were more than $38 million USD
in 1995 alone. One dramatic example
in France is the fire that occurred at
the Bordeaux Meat Packing Plant. Fire
within the combustible insulation in
the sandwich wall panels spread at
a remarkable rate of 6.89 ft / minute
(2.1 m / minute). Firefighters arrived on
the scene within 10 minutes after the
first alarm. In that time, 20,000 square
ft (6,000 square m) had already been
As a result of these and other similarly catastrophic losses, the European market introduced a series of
regulations and test methods specifically targeted at the design and use of
SWP. The fire test methods ranged from
small- to intermediate- and large-scale
tests. As a result of these initiatives,
proper specifications and good fire
safety management procedures have
significantly reduced the number of
fires involving SWP products in Europe.
Now, the insurance industry in the UK
will only certify products that have been
subject to large-scale fire tests, where
SWP products with non-combustible
cores such as stone wool insulation are
Non-combustible, fire-rated SWPs
have historically been a niche market in
North America. However, there are signs
of change. Building owners are becoming more conscientious and aware of
the devastating effects fire has on their
livelihood and the environment, thus
creating interest in fire-rated, sustainable alternatives. The migration of European manufacturers familiar with the
advantages stone wool SWPs offer is also
making a difference. In 2009, Volkswagen
committed to the construction of a new
mid-sized manufacturing facility in Chattanooga, Tennessee. The project required
one million square feet of wall panels
and, although the walls didn’t require a
specific hourly fire rating, Volkswagen
Sandwich panels consist of two outer metal sheets with a stabilizing core of insulation sandwiched between them. The
metal sheets are bonded to the insulation core with specialized adhesives, creating a seal between the insulation and the metal
skin. This, combined with the tongue and groove joint along the edges of the panels, allows the completed SWP to be moisture
resistant. Also, because sandwich panel installation requires only a limited number of mechanical fasteners (for example,
screws), the resulting constructions avoid significant thermal bridging.
Winter 2011 27
insisted a two hour fire-rated wall using
stone wool SWP be installed.
As such, changes in the market occur, pressure on the specifying community to respond has mounted. It’s
becoming increasingly clear that practices that have become institutionalized
over time need to evolve. The status quo
mindset that automatically opts for the
traditional insulating materials, mainly
EPS and PUR, is being challenged to
consider alternatives offering a better
solution. Stone wool insulation, with
its inherent ability to withstand extremely high temperatures, as well as
its additional benefits of sound absorption, moisture resistance, dimensional
stability, sustainability and long-term
thermal performance, is proving to be
an obvious choice for SWP insulation.
A more detailed examination of each
of the benefits stone wool insulation can
bring to the table should be enough to
convince even the most ardent skeptics.
not contribute to the development and
spread of fire. Stone wool insulated
SWPs can achieve non-combustible,
one-, two-, and three-hour fire ratings,
depending on the thickness of the stone
wool core. Extra minutes allow occupants of a building time to evacuate in
the event of a fire.
In comparison, SWPs manufactured using combustible insulation
materials pose a unique set of challenges. Most notably, the metal sheeting on this surface typically shields
this insulation from the effects of
sprinklers or other extinguishing systems so that a fire inside the panel
itself can spread rapidly and quickly
engulf the entire building. In addition,
many combustible insulation materials release large quantities of toxic
gases and particulate matter into the
atmosphere during a fire that can endanger occupants, firefighters and, ultimately, the environment.
Stone wool can withstand temperatures up to 2,150°F (1,172°C) and does
Stone wool insulation delivers superior acoustical performance compared
SWPs can be up to 40 ft (12 m) in length and can be installed vertically or
horizontally. A crane is sometimes used to lower larger panels into position.
28 Journal of Building Enclosure Design
to other, more conventional insulating materials like polystyrene, polyurethane and polyisocyanurate. Unlike
plastic and foam insulations, stone
wool has a unique non-directional fiber
structure, consisting of millions of tiny
voids that are effective at trapping and
dissipating sound waves, which prevents sound from traveling from one
side to the other. The higher density of
stone wool also delivers better airflow
resistance to further diminish sound
Stone wool insulated SWPs can attain an acoustic rating of 28 to 30 decibels in a standard metal skinned panel
and upwards of 35 decibels when a perforated metal skin is applied. In contrast, a traditional SWP with a plastic
core will attain an acoustic rating of
around 23 decibels.
With organizations such as the U.S.
Green Building Council and the Canada Green Building Council, and Leadership in Energy and Environmental
Design (LEED®) becoming more influential in the building industry, the onus
is on manufacturers to ensure the products they make, as well as the manufacturing processes they use to produce
them, are environmentally responsible.
As the demand for sustainable, environmentally conscious building products grows, so too does the appeal of
stone wool insulation. It is one of few
products that can save more energy
than is used to manufacture it. Once
installed, it conserves scarce energy
resources and reduces air pollution
and CO2 emissions by minimizing fuel
combustion over the long-term. In fact,
long-term studies conducted in the UK
indicate that stone wool insulation has
been able to save 128 times more energy over the course of 50 years than was
used for its production, transport and
disposal. That translates into an average energy payback only five months
after installation.
Waste created during the production
of stone wool insulation can be recycled
back into the manufacturing process to
create new products. In some instances,
manufacturers have been able to achieve
zero manufacturing waste to landfill.
Dimensional stability and
thermal performance
A significant challenge for plastic
insulation is linear shrinkage caused
by thermal cycling and/or off gassing.
Linear shrinkage causes gaps to occur
between insulation panels resulting in
diminished thermal values, loss of heat
and increased energy consumption.
Studies have shown, within a relatively
short timeframe, conventional insulations shrink significantly as a result of
off gassing.
Stone wool insulation does not offgas and it is not affected by thermal
cycling. It does not shrink, warp, curl or
cup and the fit remains stable and flush,
thereby minimizing thermal bridging.
In tests, it achieves an ASTM C356 Linear Shrinkage of 0.01 percent at 350°F
(177°C). Because there is no linear
shrinkage, the integrity of its thermal
performance is maintained, resulting in
a stable R-value over the long-term.
Moisture resistant
When tested to ASTM C1104, stone
wool insulation receives a moisture
sorption of 0.03 percent. This means
stone wool insulation does not absorb
water, yet it is vapor permeable. This
unique combination enables moisture
that has penetrated the outer membrane to disperse within the insulation,
effectively preventing the formation
of blisters and bulging of the exterior
metal skin.
Additionally, it is completely resistant to rot and corrosion and will not
promote nor support fungi or bacterial growth. The result of this is a safer,
healthier indoor environment.
North American code
There are numerous requirements
applied to SWPs, depending upon
where and how the products are used.
The choice and requirements related
to the appropriate fire tests are governed by many factors. Considerations
include building type, size and use, as
well as distances to adjacent property
lines and the percentage of unprotected openings in the exterior wall such
as non-fire-resistant windows and
While both Canadian and U.S. codes
(for example, the 2005 National Building
Code of Canada and the 2009 International Building Code) contain specific
provisions for SWP applications incorporating “foamed plastics”, these provisions do not apply generically to all SWP
products, particularly those that do not
contain foamed plastic cores.
In terms of fire performance, North
American code requirements are separated into three groups:
1. Flame spread, combustibility and
interior fire growth;
2. Exterior wall applications; and
3. Fire resistance rated assemblies.
Each code has rules based on the
types of materials used in the SWP and
the purpose of the wall. SWP incorporating foamed plastics have various
additional restrictions related to building height, sprinkler protection, use of
thermal barriers and distance between
adjacent property lines. In contrast,
SWP products with non-combustible
cores, such as stone wool, are far less
restricted and complicated to use from
a building code perspective.
For code compliance, the main advantage of using SWP with non-combustible
cores can be summed up in one word:
simplicity. All the confusion, complexity
and uncertainty can be eliminated simply
by specifying a SWP with a non-combustible core such as stone wool.
Stone wool age is at hand
The North American building industry is entering an exciting new era in
which green building practices are taking
precedence. Going forward, sustainable
building products delivering solid longterm returns, both economically and socially, will increasingly be the preferred
option. SWP products with a non-combustible stone wool insulation core can
play a pivotal role in future buildings.
Given the inherent economic and environmental advantages of stone wool
and the cost effectiveness of SWP construction versus brick, granite or precast, there is a very compelling business
case when you put the two together.
In the end, it’s about making a choice
between the past and the future. Perhaps it is time we consciously decide to
move beyond the age of using conventional combustible insulating materials
and into the non-combustible stone
wool age of safe, re-usable and sustainable building products and practices.n
Jim Miller is the North American
Sales Manager for OEM|Roxul Inc. and
has worked in the insulation business
for 14 years. He spent 4 years testing
products and learning the best products
for the best applications and 12 years
working in sales (residential, commercial, industrial and SWP).
Winter 2011 29
Industry Update
BEC Corner
By Whitney E. Okon, Applied Building
BEC-Charleston wrapped up its fifth
year of bringing building science to
South Carolina’s Lowcountry design and
construction community. This past fall
we enjoyed presentations entitled Huffing and Puffing: The Effects of HVAC on
the Building Enclosure, by Lew Harriman,
Restoration as the Ultimate Act of Sustainability, by Christopher Perego, Geothermal Heat Pumps, and The Three R’s:
Repairs, Renovations and Retrofits in Hot,
Humid Climates, by Joseph Lstiburek.
BEC-Charleston has, for the second
year, invited both collegiate and high
school students to take part in our BEC
scholarship program. The collegiate
applicants were undergraduate and
graduate students who demonstrated
an interest, aptitude and enthusiasm
for the built environment, as displayed
by their academic or extracurricular efforts in matters of architecture, building science and/or construction. The
collegiate award for 2010 was $1,000.
The selection process was made by
the seated Board of Directors of BECCharleston, with preference given
to applicants that demonstrated an
understanding of building envelope
design and its purpose relative to energy efficiency, air, moisture and environmental control. In 2011, BEC will
join forces with the local Charleston
ASHRAE chapter to support high school
students in three regional science fairs.
Monetary awards for achievement in
building science and engineering will
be presented. The goal is to spark interest in young adults and educate them
on opportunities in careers related to
building science.
BEC-Charleston has over 200 professionals on our membership list
and greets about 40 to 50 members
at each meeting. For additional information, contact Whitney Okon at
or Ken Huggins (Communications) at
By Richard Fencl, AIA, CSI, LEED AP,
BEC-Chicago is focusing on monthly
programs and is attempting to “elevate”
the topics to target mid- and senior-level
architects, engineers and those interested in the building envelope.
In September 2010, Chicago-BEC
raised $700 to sponsor Andre Dejarlais
from the Oak Ridge National Laboratory
to come to Chicago to speak to our group
on the cutting-edge research that Oak
Ridge is conducting on building envelope
In October, Roger Skluzacek, Technical Services Manager with Viracon, addressed the council on heat soaking and
glass distortion issues.
In November, forensic firms Wiss, Janney, Elstner Associates, Inc., and Raths &
Johnson presented two case studies on
façade problems and the fixes that were
In December, Mark Frisch of Solomon
Cordwell & Buenz presented their double
skin façade design for the library building at Loyola University in Chicago. This
is Chicago’s first true double-skin design!
We have also elected a new treasurer,
Ken Lies of Raths, Raths & Johnson.
Upcoming programs for 2011 include
discussions on moisture movement in
roofing, siphonic drainage, foam plastic
used in exterior walls (NFPA 285) and
post occupancy evaluation.
By Robert Matschulat, AIA, CSI, CCS, CEFPI, NCARB, edutecture LLC
BEC-Colorado is getting ready to celebrate our sixth anniversary and despite
the sluggish economy, we continue to
achieve new levels of success. Attendance at our monthly first-Wednesday
programs has stabilized somewhat but
still averages more than 35 participants
per session. We continue to explore diverse topics in a variety of venues. Our
July session on wind tunnel testing was
conducted at the facilities of CPP Inc. in
Fort Collins, Colorado, and our August
event was held at Bandimere Speedway.
We are grateful for the generosity of JE
Dunn for the use of its offices for recent
and scheduled sessions into 2011.
The following are the programs that
were presented since our 2009 report. In
December 2009, we hosted a contractor’s
roundtable; January 2010’s presentation was Green Roofs and Garden Roofs;
February’s presentation was Optimizing
Performance in Commercial Fenestration; March was Rainscreen as a Moisture
Management Strategy; April’s presentation was Below Slab Moisture—Vapor
Barriers, Nuisance or Necessity; May’s
presentation was NFRC Ratings—What
They Mean and How They are Determined; June’s presentation was Applied
Concrete Sealers; July’s presentation was
Wind Tunnel Testing at CPP Inc.; in August we hosted an energy code roundtable, sponsored by RW Specialties, Inc.; in
September we held the annual seminar
Building Enclosure Retrofits for Energy
Performance, presented by Wagdy Anis,
FAIA, of Wiss Janey Elstner Associates,
Inc.; in October we held the annual BECColorado planning meeting; November’s
presentation was Commercial Window
Energy Performance; and December’s
presentation was A Case Study of Roof Repair to Indoor Pool Building In Colorado
High Country.
New BEC Colorado leadership was
elected at the October 2010 annual planning meeting. Our new Chair is Chip
Weincek, AIA, LEED AP, CWA Architecture; our Programs Director is David Milliken, AIA, David Milliken Architect LLC;
and our Secretary is Will Babbington, Assoc. AIA, PE, LEED AP.
The success of BEC-Colorado is due
in large part to the support of our sponsors: A-1 Glass Inc., Andersen and Eagle
Windows, Building Consultants & Engineers Inc., Carlisle, Elliott Associates
– Vapor Shield, Fentress Architecture,
Georgia Pacific, Grace, HDR Architecture, Reward Walls, R/W Specialties, Inc.,
Tyvek and Sto Corporation.
BEC-Colorado plans to host a fifth annual BEC seminar in September.
Winter 2011 31
Building on a solid record of accomplishments and boosted by signs of an
improving economy, BEC-Colorado anticipates new levels of success in 2011.
By Justin Boone, AIA, CDT, LEED AP, Wiss,
Janney, Elstner Associates, Inc.
BEC-Houston has had an exciting year
full of many positive changes. We now
have a multi-disciplinary 12-member governing board to guide and run the organization. Additionally, sub-committees have
been established for programs, building
enclosure commissioning and educational outreach. Other changes included the
addition of paid memberships and corporate sponsors to fund our activities. We relaunched the organization in January with
a well-attended networking event.
Our technical presentations this year
covered topics including air barrier testing, climate specific green roof design, kinetic enclosures, non-destructive testing,
forensic investigations and façade access.
In an attempt to widen our available pool
of presenters, we conducted a successful
experiment by having one of our presentations given as a live webinar by a presenter in Canada.
In October, we brought in Dr. Joseph
Lstiburek to teach a one-day seminar at
the Rice University School of Architecture
entitled Building Science and Detailing for
Hot Humid Climates. We hope to continue
our new found momentum into 2011.
By Dave Herron, Herron+Partners
The Kansas City-BEC continues to
host a variety of sessions, from walking
tours of buildings under construction
to the proper design and installation of
roofing curbs. For our upcoming presentations, we will have Peter Poirier,
Technical Director of Building Envelope
Solutions from Tremco Incorporated, and
John Edgar, Technical Manager, Building
Science at Sto Corp. MIAMI
By Karol Kazmierczak (Kaz), AIA,
Miami slowly cooled down after the
AIA National Convention hosted in June,
2010. BEC-Miami continues to meet
monthly on every third Tuesday.
Recent seminars included Charles E.
Rogers, Esq., on Professional Liability and
the Building Enclosure, Dean Kauthen of
Centria on Metal Wall Systems, Karen L.
Warseck on Common Mistakes in Designing a Roof, Jim Simpson from Quigley on
Below Grade Waterproofing, Carl Kuhn of
Soprema on Roofing, John H. Thomas of
BASF on EIFS, and Robert Erwin of Tremco on Air Barriers.
This year we plan to arrange a series of
half-day workshops on building sciences
and technology. We moved our webpage
to www.bec-miami.org. Look for a calendar of events there.
those molded into rock face shapes and
brick-like veneer. In November, at the request of our
BEC, R. Christopher Mathis of the BETEC
Board and Mathis Consulting came to the
76th Annual AIA Minnesota Convention
to present an impressive monologue on
his perspective of sustainability.
In December, Terry Dieken, owner of
Extreme Panel Technologies, presented
information about different methods and
materials used in fabricating SIPs, ways
in which the SIPs are assembled onsite
and factors to consider to avoid pitfalls.
It’s been another great year!
By Judd Peterson, AIA, Judd Allen Group
Last May, BEC-Minnesota participant
Tim Eian, who has presented to our group
about passive house design, completed
construction on one of the first few passive houses in Minnesota. Check out his
blog at www.passivehouseinthewoods.
In June, we had a roundtable brainstorming session to develop a list of
helpful research information that could
be pursued by the U.S. Deptartment of
In July, BEC-Minnesota opted to enjoy the new Target Field for the Minnesota Twins and followed that up with a
tremendous presentation by Michael
Bjornberg and Ginny Lackovic of HGA
Architects about their Minnesota State
Capitol Dome Renovation Project. They
experienced numerous challenges with
moisture control through several layers
of dome shell construction, in addition
to historic, original structural and ornamental detailing.
Coleman Jones of Stone Panels, Inc.
discussed lightweight honeycomb reinforced stone cladding systems with our
committee. This thin stone veneer applied to an aluminum honeycomb frame
is to be used as an exterior rainscreen
and/or interior wall cladding.
At the encouragement of AIA-Minnesota’s Jennifer Gilhoi, we sought mission
statements for our BEC in participation with other committees of our AIA
Paul Schied of Anchor Block dropped
by to share the latest information on cast
concrete masonry units, particularly
By David C. Young, P.E., RDH Group
The Portland-BEC chapter is progressing well into the 2011 season and is
continuing to grow both in membership
and attendance at our monthly meetings.
We have received very positive feedback
on our recently-initiated dues structure,
which allows us to meet the expenses of
a growing, successful chapter. This new
structure is also allowing us to import
prospective national speakers who will
further enhance our program. We still
offer a free box lunch to members attending our monthly meetings, generously provided by our local sponsors.
We are very pleased with the quality
of our program this season and we are
heading toward a curriculum-type programming approach. For now, we are using this idea as a framework for choosing
speaker topics for the season, beginning
with building science basics through
below-grade, roofing, fenestration, walls
and HVAC. Our September speaker was
able to kick off the fall program by making building science fundamentals both
informative and entertaining. An excellent presentation on below-grade waterproofing systems followed in October.
Building envelopes and energy balances
was the topic in November 2010. The
presentation highlighted the design of a
dynamic solar shading and glare control
system for UC San Diego’s new Health
Science Research Laboratory. The presenter hinted about some very exciting
energy research to be embarked upon
for a new enthalpy recovery ventilated
façade system. We are looking forward
Continued on page 35
Winter 2011 33
Continued from page 13
can be a very effective way of not only
refurbishing the old roofing surface but
also improving the energy performance
of existing roofs. PV-PCM attics had average winter heat losses that were 30 percent
lower than those from conventional attics
covered with shingles. Moreover, traditional shingle roofs showed heat losses that
were 80 percent higher than those from
PVC-PCM roofs at night.
The presented test results show that
re-roofing using metal panels with PV
technology and PCM heat sink can be a
very effective way of repairing existing
roofs without generating solid waste in
the future. This new sustainable way of reroofing not only improves the overall performance of existing roofs, it will generate
inexpensive solar electricity.
Jan Kosny, PhD, is from the Fraunhofer
Center for Sustainable Energy Systems in
Cambridge, Massachusetts. Before 2010,
Dr. Kosny worked for Oak Ridge National
Laboratory (ORNL) in Oak Ridge, Tennessee. Kaushik Biswas, William Miller and
Phillip Childs are with the ORNL. The authors would like to acknowledge the U.S.
Department of Energy, in particular Marc
LaFrance, for funding the ORNL’s phase
change material research program. This
project was also performed thanks to the
direct funding and in-kind contributions
from the members of the Met­al Construction Association.
A full list of references for this article
is available upon request. Please email
Continued from page 33
to great upcoming presentations in the
New this year, we are broadcasting
live video of our presentations over the
internet. Our meetings are held on the
first Tuesday of each month from 12:00
pm to 1:30 pm (Pacific Time). We invite
everyone to join in via the web during
our meetings at http://pdx.uoregon.edu.
By Michael Zensen, Cannon Design
BEC-St. Louis offered a program on
envelope testing in October 2010, which
was hosted by the Masonry Institute of
St. Louis. The program was presented
in three parts: an introduction to testing methodologies, a case study project and a panel discussion about the
challenges of testing. Many thanks go
to Tod Huddleston of Edward Jones for
bringing an owner’s perspective on the
cost/value of testing, Gary Atkins of McCarthy Construction and John Emert of
Arcturis for their willingness to present
the Edward Jones Case Study.
This program uniquely touched every one of our membership constituencies, including designers, engineers,
owners, product representatives, contractors and subcontractors.
The focus for 2011 is on Integrated
Mechanical, Envelope and Energy Analysis. A calendar of programs is posted at
our website, www.bec-stl.org. We have
also created a region-wide continuing
education calendar in an effort to fulfill
our exchange and connection mission.
We are in the post-production of webinars of our programs and some are already available on our website. n
Winter 2011 35
Buyer’s Guide
Masonry and BIM Modeling
Endicott................................................. 3
Air and Vapor Barriers
Hohmann & Barnard, Inc............. 29, 37
Industrial Glass Suppliers
PPG Industries.............................. 38, 39
Architectural Glass and
Oldcastle Building Envelope™..... 20, 21
Industrial Sealants
Tremco Inc. Commercial Sealants...... 13
Air Barrier Association of America..... 34
The Glass Association......................... 32
JAG Architecture
Omegavue / Judd Allen Group............ 30
Below Grade Water and
Containment Barriers
Polyguard.............................................. 4
B&B Lighting Supply, Inc................... 29
Water Intrusion Test Equipment
and Training
The RM Group, LLC.......................... 37
Masonry Anchoring Systems
Hohmann & Barnard Inc.............. 29, 37
Water Proofing
Sto Corp........................................... IFC
Building Sciences and
Restoration Consultants
Read Jones Christofferson.................. 35
Mineral Wool Insulation
Roxul Inc............................................... 6
Structural Engineering Design
and Consultants
WJE..................................................... 16
Consulting, Commissioning,
Engineering Testing, Certifaction
and Inspections
Architectural Testing.......................OBC
Diagnostic Tools
Retrotec Energy Innovations Ltd..10, 14
The Energy Conservatory...................... 8
Enginered Curtain Walls and
Window Walls
Oldcastle Building Envelope™..... 20, 21
Entrance Systems Spare Parts
Oldcastle Building Envelope™..... 20, 21
Winter 2011 37