Quality and Durability of ETICS
The longevity of building components such as External Thermal Insulation
Composite Systems (ETICS)1) is increasingly in focus of both public awareness
as well as regulatory bodies when demanding for sustainable solutions in the
construction industry. It is generally understood that high quality products
can extend the lifecycle of existing and new buildings – thus helping to
conserve resources.
More stringent energy saving regulations in many countries have become
effective and contributed to the rapid growth of ETICS as a façade
technology. Today, these systems are being applied on many new buildings
as well as in renovation projects world wide. By insulating outside the structure,
ETICS reduce air infiltration, stabilise the interior environment and
reduce energy consumption.
1) Also referred to as Exterior Insulation and Finish Systems (EIFS)
Polymer Additives in ETICS Application
2.15
2.10
2.05
Structural viscosity
As mortar layers are an essential part of ETICS, their durability and
resistance to a number of factors are key for the longevity of the
whole system. The adhesive mortar must provide high tensile bond
strength for a reliable adhesion of the insulation board to the wall
substrate. The finishing layers have to withstand typical influences
resulting from long-term outdoor exposure such as rain water,
temperature fluctuations and other environmental effects like air
pollution. In addition, they protect the following layers from
mechanical impact.
2.00
1.95
1.90
1.85
1.80
1.75
19.0
20.0
21.0
22.0
23.0
24.0
25.0
23.0
24.0
25.0
Water level [%]
Dow Construction Chemicals offers a range of cellulose ethers,
redispersible polymer powders and liquid latex products as additives
for mortar formulations responding specifically to these requirements.
0.15
0.14
Water level [%]
Applicators can choose between cementitious and dispersion based
adhesives and renders for ETICS. In both cases it is of paramount
importance for manufacturers to select additives for the mortar
formulations which enable the production of high performance,
durable system components thus a sustainable insulation system.
0.13
0.12
0.11
0.10
19.0
20.0
21.0
22.0
Bond strength to EPS [N/mm2]
In cementitious systems, cellulose ethers help to control fresh mortar
properties like water demand, workability, open time and water
retention. The ease of application correlates with the shear thinning
of the mortar, expressed as structural viscosity. The higher the water
demand of the cellulose ether, the stronger the mortar consistency
will depend on the shear rate resulting in pleasant workability.
The bond strength of cementitious mortars, however, decreases with
higher water levels. This conflicting trend needs to be well balanced
by the formulator (see figure 1).
Redispersible polymer powders (RDP) are additional binders in dry-mix
mortar formulations which make sure that the mineral based mortar
adheres to the surface of the polystyrene insulation panel. It also helps
to improve the impact resistance of the mortar/polystyrene interface.
Figure 2 illustrates the impact of 3 Joules to an ETICS sample with and
without the addition of redispersible polymer powders.
ETICS mortars need to be hydrophobically modified to repell the water
from the system in case of rain. Hydrophobicity is either incorporated
in the mortar by accordingly modified redispersible polymer powders
or by separate additives wich are either based on alkali salts of fatty
acids or by silane based products.
Figure 1: Structural mortar viscosity and bond strength
controlled by water demand
Sample a)
Sample b)
Figure 2: Impact of 3 Joules to ETICS samples without
RDP (sample a) and with 3% RDP (sample b)
It is also common to install ETICS with dispersion based mortars and
adhesives without using cementitious products at all. These renders,
mainly top coats, can be either based on styrene acrylic or pure
acrylic polymers. Products based on acrylic emulsions generally
enable a very good durability, a high resistance to dirt pick-up and a
good workability. Dow is offering a number of APEO free which
support these important end-product characteristics. Although top
coats produced with styrene acrylic emulsions impart comparable
performance in such areas as initial gloss and application properties,
pure acrylic emulsions have shown to be superior in terms of their
longterm behaviours.
In summary, our products help to:
– deliver high adhesion strength and reliably adhere the
entire ETICS system
– make the ETICS system durable by providing resistance
to water, UV-light, dirt pick-up and cracking
– provide improved water-retention and good workability
for efficient application
Product Portfolio
WALOCEL™ methyl cellulose, DOW™ Latex
Powder and PRIMAL™, UCAR™ acrylic emulsion
polymers
In the region, Dow Construction Chemicals offers a range
of products for high-quality durable adhesive, base and
top coats.
For more information please see the respective
brochures, for further requirements please consult
the regional Dow sales representative.
Dow Construction Chemicals –
Where Quality Building Starts
With a portfolio of established brands such as PRIMAL™ and
UCAR™ acrylic emulsion polymers, WALOCEL™ and METHOCEL™
cellulose ethers, DOW™ Latex Powders, OROTAN™ dispersants,
ACRYSOL™ synthetic thickeners and AQUASET™ thermoset
binders, Dow Construction Chemicals is a leading supplier to
construction product formulators around the world. The business
offers broad technology platforms and application know-how in
acrylic, redispersible latex powder, and cellulosic technology.
Dow Construction Chemicals brings together the combined
resources and 40-year industry experience of Rohm and Haas and
Dow Wolff Cellulosics to offer in-depth technical knowledge and
effective formulation development experience to manufacturers
of building and construction products around the world, supported
by global research, technical service and manufacturing facilities.
The reliability and high-quality of binders and products from Dow
Construction Chemicals form the heart of many innovative products
that have become industry essentials. Applications range from tile
adhesives, renders, plasters, ETICS, self-levelling underlays
to repair mortars, waterproofing membranes, roof coatings among
others.
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Note
Please follow the instructions indicated on the respective
SDS (Safety Data Sheet). The information and data contained
in this brochure do not represent exact sales specifications.
The features of the products mentioned may vary. The information
contained in this document has been provided in good faith,
however it does not imply any liability, guarantee or assurance
of product performance. It is the pur­chaser’s responsibility
to determine whether these Dow products are suitable for the
application desired and to ensure that the site of work and
method of application conform with current legislation. No
licence is hereby granted for the use of patents or other industrial
or intellectual property rights. If Dow products are purchased,
we advise following the most up-to-date suggestions and
recommendations.
Dow Chemical IMEA GmbH
P.O. Box 7893, Dubai
United Arab Emirates
Phone +971 4 4537 000
Fax +971 4 4537 117
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About Dow
Dow (NYSE: DOW) combines the power of science and technology
to passionately innovate what is essential to human progress.
The Company connects chemistry and innovation with the principles
of sustainability to help address many of the world’s most challenging
problems such as the need for clean water, renewable energy
generation and conservation, and increasing agricultural productivity.
Dow’s diversified industry-leading portfolio of specialty chemical,
advanced materials, agrosciences and plastics businesses delivers
a broad range of technology-based products and solutions to cus­
tomers in approximately 160 countries and in high growth sectors
such as electronics, water, energy, coatings and agriculture. In 2011,
Dow had annual sales of $60 billion and employed approximately
52,000 people worldwide. The Company’s more than 5,000 products
are manufactured at 197 sites in 36 countries across the globe.
References to “Dow” or the “Company” mean The Dow Chemical
Company and its consolidated subsidiaries unless otherwise
expressly noted. More information about Dow can be found at
www.dow.com.
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