SECTION 23 31 00 Outside Ductwork—[Foil/Sealant System--Sealing Ductwork
with a Sealant and the foil faced FG-701]
This guide specification has been prepared by Hardcast, Carlisle HVAC Incorporated to assist design
professionals in the preparation of a specification section covering either brush applied, caulk, spray applied
sealant/mastic and a rolled sealant for sealing metal, flex, duct board duct systems.
This specification may be used as the basis for developing either a project specification or an office master
specification. Since it has been prepared according to the principles established in the Manual of Practice
published by The Construction Specifications Institute (CSI), this guide specification may be used in
conjunction with most commercially available master specifications sections with editing.
The following should be noted in using this guide specification:
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Optional text requiring a selection by the user is enclosed within brackets, e.g.: "Section [01330]
[_____]."
Items requiring user input are enclosed within brackets, e.g.: "Section [_____ - _______]."
Optional paragraphs are separated by an "OR" statement, e.g.: [OR]
Metric equivalents to inch-pound units follow the inch-pound (I-P) units and are contained within
parenthesis. Metric measurements are rationalized units based on the SI system of measurement.
Delete either the inch-pound or metric units of measure depending on project requirements; do not
include both units in a project specification, as conflicting requirements could result.
This guide specification is available in both hard copy and a variety of electronic formats to suit most popular
word processing programs and operating platforms. Please contact Hardcast at http://www.carlislehvac.com
or at (800) 527-7092 for additional copies and for information on available electronic formats.
Part 1 - GENERAL
1.01
RELATED DOCUMENTS
A. Drawings and general provisions of the Contract, including General and Supplementary
Conditions and Division 01 Specification Sections, apply to this Section.
B. Specifications throughout all Divisions of the Project Manual are directly applicable to this
Section, and this Section is directly applicable to them.
Edit the following paragraphs to coordinate with other sections of the project manual.
Related Sections:
Section [23 07 13 - Mechanical Insulation] [_____ - ________]: Duct insulation.
Section [23 33 00 - Ducts] [_____ - ________]: Metal ductwork.
1.02
SUMMARY
A. Provide duct sealants/mastic and rolled sealant for duct seams, joints and duct wall
penetrations and installation for complete first class HVAC systems; install ductwork, flexible
duct, hangers, supports, sleeves, flashings, vent flues, and all necessary accessories as
indicated in the Contract Documents. Provide any supplementary items necessary for proper
installation that make the systems operable, code compliant and acceptable to the authorities
having jurisdiction.
1.03
DEFINITIONS
A. Duct Joint: Transverse joint between duct sections including girth joints, branch and subbranch intersections, duct collar tap-ins, fitting subsections, louver and air terminal
connections, access doors and frames, and abutments to building structure.
B. Duct Seam: Longitudinal joint between duct sections. Spiral lock seams in factory fabricated
round or oval ducts are excluded.
C. Duct Penetration: locations where the duct wall is penetrated.
1.04
REFERENCES
A. The latest published edition of a reference shall be applicable to this Project unless identified
by a specific edition date.
B. All reference amendments adopted prior to the effective date of this Contract shall be
applicable to this Project.
C. All materials, installation and workmanship shall comply with the applicable requirements and
standards addressed within the following references:
1. American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE)
a. Handbook of Fundamentals; Duct Design.
2. American Society for Testing and Materials (ASTM)
a. E 84 – Standard Test Method for Surface Burning Characteristics of Building
Materials.
b. C-731 – Standard Test Method for Extrudability, after Package Aging of
Latex Sealants
c. D-2202 – Standard Test Method for Slump of Sealants
3. Sheet Metal and Air Conditioning Manufacturers National Association (SMACNA):
a. Handbook of HVAC Systems and Equipment; Duct Construction.
b. Rectangular Industrial Duct Construction Standards
c. Round Industrial Duct Construction Standards
d. HVAC Air Duct Leakage Test Manual
e. Duct Cleanliness for New Construction Guidelines
4. Underwriters Laboratories, Inc. (UL):
UL 181 Listed products or systems are used with Spiral and Rectangular
Galvanized, Stainless, Aluminum, and PVC coated sheet metal duct and are not
limited to rigid or flexible fiberglass air ducts and air connectors.
a. UL 181 A-M Mastic Closure for Use with Rigid Fiberglass Ducts
b. UL-181 BFX Standards for use on Flexible Air Ducts and Closures
c. UL 181 B-M Mastic Closure for Use with Flexible air Ducts
d. UL 723 Standard Test Method for Surface Burning Characteristics of
Building Materials.
5. FDA approval based on criteria established by Food Safety and Inspection Services
(FSIS)
NSF/AWSI Standard 61 Pass Michigan Department of Quality Criteria (Part 201/213)
Acceptable Indoor Air Concentrations
1.05
QUALITY ASSURANCE
A. Manufacturer: Firm specializing in manufacturing in the work of this Section with minimum 20
years documented experience.
B. Installation contractor: shall have minimum three years documented experience specializing in
performing the work of this section.
C. Installation of HVAC sealant shall be performed by qualified Journeyman.
1.06
SUBMITTALS
A. PRODUCT DATA:
Provide the following information for each sealant system furnished on the Project:
Sealant name, lot # and type:
1. Sealant system design pressure.
2. Duct material.
3. Duct gage.
4. Transverse joint methods.
5. Longitudinal seam type.
Edit the following paragraph to coordinate with Division 1 statements.
Submit under provisions of Section [01330] [____].
Product Data:
In the following paragraph, retain the bracketed text where a fire-rated system is required.
Sealant System: Include product description, [surface burning characteristics,] performance
characteristics, and installation instructions.
In the following paragraph, retain the bracketed text where a fire-rated system is required.
Test Reports - Sealant System: Indicate [surface burning characteristics,] pressure classes, and
seal classes.
Certification: Manufacturer's certification that Products meet or exceed specified requirements.
1.07
1.08
DELIVERY, STORAGE AND HANDLING
A. Deliver products to the Project Site and store and protect products under provisions of Division
01 and Division 20.
B. Store materials in protected, dry area, at a temperature within manufacturer's recommended
storage range of 35 deg. F to 110 deg. F (1.7C to 38C).
PROJECT CONDITIONS
A. Environmental Requirements: Do not apply products when ambient or surface temperature
temperatures are lower or higher than those recommended by manufacturer of 35 deg. F to
110 deg. F (1.7C to 38C)
PART 2 – PRODUCTS
2.01
GENERAL
A. All materials shall meet or exceed all applicable referenced standards, federal, state and local
requirements, and conform to codes and ordinances of authorities having jurisdiction.
B. Acceptable Manufacturer: Hardcast, Carlisle Coatings and Waterproofing Incorporated, 900
Hensley Lane, Wylie, Texas 75098, (800) 527-7092.
2.02
MATERIALS - DUCT SEALANT SYSTEMS
A. Duct Sealing: All ductwork, regardless of system pressure classification, shall be sealed in
accordance with Seal Class A, as referenced in SMACNA Standards. All transverse joints,
longitudinal seams, and applicable duct wall penetrations shall be sealed by applying one layer
of sealant at a minimum of 20 to 30 wet mils.
1.
Sealant shall be water based latex UL 181B-M non-reinforced sealant conforming to the
product specifications with flame spread of 0 and smoke developed of 0. Sealants shall
be similar to Hardcast Iron-Grip 601 with the following physical properties:
a. Shore Hardness: >20
b. Flexibility on ¼-inch mandrel: Passes
c. Freeze/Thaw Stability: Passes 5 cycles
d. Service temperature: -20 to plus 200 degrees F (minus 29 to plus 93 degrees C).
e. Resistance to mold, mildew and water: Excellent
f. UL 181B-M: Passes
g. Surface burning characteristics: Flame spread/smoke developed rating of 0/0,
tested in accordance with UL
h. Seal classes: All SMACNA Classes.
i. All pressure classes (+/-): SMACNA 1/2, 1, 2, 3, 4, 6, and 10 inches water gauge.
j. City of Los Angeles Approval: RR# 8427
k. FDA approval based on criteria established by Food Safety and Inspection
Services (FSIS)
l. NSF/AWSI Standard 61 Pass
m. Michigan Department of Quality Criteria (Part 201/213) Acceptable Indoor Air
Concentrations
OR [reinforced mastic]
A.
Duct Sealing: All ductwork, regardless of system pressure classification, shall be sealed in
accordance with Seal Class A, as referenced in SMACNA Standards. All transverse joints,
longitudinal seams, and applicable duct wall penetrations shall be sealed by applying one layer
of sealant at a minimum of 20 to 30 wet mils.
1.
Sealant shall be water based latex UL 181A-M, B-M reinforced sealant conforming to the
product specifications with flame spread of 0 and smoke developed of 0. Sealants shall
be similar to Hardcast Versa-Grip 181 with the following physical properties:
a. Shore A Hardness: >20
b. Flexibility on ¼-inch mandrel: Passes
c. Freeze/Thaw Stability: Passes 5 cycles
d. Service temperature: -20 to plus 200 degrees F (minus 29 to plus 93 degrees C).
e. Resistance to mold, mildew and water: Excellent
f. UL 181A-M: Passes
g. UL 181B-M: Passes
h. Surface burning characteristics: Flame spread/smoke developed rating of 0/0,
tested in accordance with UL
i. Seal classes: All SMACNA Classes
j. All pressure classes (+/-): SMACNA 1/2, 1, 2, 3, 4, 6, and 10 inches water gauge
k. City of Los Angeles Approval: RR# 8427
l. FDA approval based on criteria established by Food Safety and Inspection
Services (FSIS)
m. NSF/AWSI Standard 61 Pass
n. Michigan Department of Quality Criteria (Part 201/213) Acceptable Indoor Air
Concentrations
OR [spray applied non-reinforced system]
A.
Duct Sealing: All ductwork, regardless of system pressure classification, shall be sealed in
accordance with Seal Class A, as referenced in SMACNA Standards. All transverse joints,
longitudinal seams, and applicable duct wall penetrations shall be sealed by a water based
spray applied at 20 to 30 wet mils.
1.
Sealant shall be water based latex UL 181 B-M non-reinforced sealant conforming to the
product specifications with flame spread of 0 and smoke developed of 0. Sealants shall be
similar to Hardcast Spray-Seal with the following physical properties;
a. Shore A Hardness: >20
b. Flexibility on ¼-inch mandrel: Passes
c. Freeze/Thaw Stability: Passes 5 cycles
d. Service temperature: -20 to plus 200 degrees F (minus 29 to plus 93 degrees C).
e. ASTM 5590; Resistance to mold, mildew and water: Excellent
f. ASTM D412: Tensile Strength; 175 psi
g. ASTM 1305: Low Temperature Crack Bridging; pass @ 0 F
h. ASTM 1970: Low Temperature Flexibility: pass @ -5 F
i. UL 181B-M: Passes
j. Surface burning characteristics: Flame spread/smoke developed rating of 0/0,
tested in accordance with UL
k. Seal classes: All SMACNA Classes.
l. All pressure classes (+/-): SMACNA 1/2, 1, 2, 3, 4, 6, and 10 inches water gauge.
m. FDA approval based on criteria established by Food Safety and Inspection
Services (FSIS)
n. NSF/AWSI Standard 61 Pass
o. Michigan Department of Quality Criteria (Part 201/213) Acceptable Indoor Air
Concentrations
AND
Include the following paragraph for duct that operates in the range of +/- 10 in. w.g. in a UL Classified rolled
duct sealant rated tape system. This rolled sealant should be used on an interior, exterior or sub-grade
locations on PVC coated duct and to seal joints, seams and duct wall penetrations.
A.
Duct Sealing: All ductwork, regardless of system pressure classification, shall be sealed in
accordance with Seal Class A, as referenced in SMACNA Standards. All transverse joints,
longitudinal seams, and duct wall penetrations shall be sealed by a 30 mil Rolled Sealant.
1.
Rolled Sealant shall be comprised of a 2-mil foil faced with 28 mils of butyl
adhesive/sealant conforming to the product specifications. Rolled Sealant shall be
similar to Hardcast Foil-Grip 701 with the following physical properties;
a. Peel Strength: 16 lbs. per linear inch.
b. Tensile strength: 955 psi
c. Elongation: 560%
d. Flexibility: Excellent
e. Bonding time: Instant with full bond in 24 hours
f. Resistance to mold, mildew and water: Excellent
g. Weather Resistance per ASTM G-53 @ 2000 hours QUV: passes
h. Service temperature: -20 to plus 200 degrees F (minus 29 to plus 93
degrees C).
i. Surface burning characteristics: Flame spread/smoke developed rating of
20/40, tested in accordance with UL 723
j. VOC: 0 g/l
k. Seal classes: All SMACNA Classes
l. All pressure classes (+/-): SMACNA ½, 1, 2, 3, 4, and 6 inches water gauge
Part 3 - EXECUTION
3.01
GENERAL
A.
Installation shall meet or exceed all applicable federal, state and local requirements,
referenced standards and conform to codes and ordinances of authorities having
jurisdiction.
B.
All installation shall be in accordance with manufacturer’s published recommendations.
C.
Cleanliness:
1. Before installing sealant, Surface must be dry and be free of dirt, oil, grease, and loose
or foreign matter that could impair adhesion wipe ductwork to a visibly clean condition.
2. During construction, provide temporary closures of metal or taped polyethylene on open
ductwork and duct taps to prevent construction dust or contaminants from entering
ductwork system. Seal ends of ductwork prior to installation to keep ductwork interior
clean. Remove closures only for installation of the next duct section.
3. During duration of construction, maintain the integrity of all temporary closures until air
systems are activated.
4. Follow the Advanced Level requirements as found in the SMACNA Duct Cleanliness for
New Construction Guidelines.
3.02
INSTALLATION OF MASTIC/SEALANT DUCT SYSTEM
A. One Part Sealant System:
General Application on Metallic Duct Systems
Apply one-part sealant system at a 20 to 30 wet mil thickness with a
brush, putty knife; caulk gun or Spray to duct joints, fasteners and
seams.
Tool, if necessary, caulk bead with putty knife or brush.
Let dry per manufacturer data sheet of a minimum of 48 hours.
[OR]
A. One Part Spray Applied Sealant System
Use a Hardcast approved airless sprayer capable of application
pressure up 2,000 psi spraying through a minimum .111 tip.
Apply in a smooth application perpendicular to the substrate at a rate of
20 to 30 wet mils to joints, seams and duct wall penetrations per
manufacturer’s technical data sheet.
Let dry per manufacturer data sheet of a minimum of 48 hours.
[AND]
B. Installation of Rolled Sealant Tape:
Cut desired length for each side of the ductwork; peel off release liner
and center over joint, seam or penetration. The rolled sealant should
completely cover the sealant. Use hand pressure to place the rolled
sealant followed by a squeegee application. Lap tape end 2 inches (50
mm minimum). Squeegee rolled sealant to insure bond and complete
adhesion to the duct.
Instant adhesion requires precise positioning. Not re-positional.
Four-Bolt flange requires applying corner pieces as shown in detail
Foil/Sealant-2 prior to applying the edge strips.
3.03
FIELD QUALITY CONTROL
A. Allow duct sealant system to cure minimum 48 hours before pressure testing for the fluid
applied Sealants. Rolled sealants can be tested immediately with duct leakage tester.
B.
Ductwork leakage testing and/or inspection shall be performed prior to installation of external
ductwork insulation.
C.
Duct systems designed to operate above 3 in. w.g. (positive or negative) shall be pressure
tested according to SMACNA test procedures (HVAC Air Duct Leakage Test Manual). Notify
Owner minimum seven (7) calendar days in advance of leakage testing
1. Design pressure for testing ductwork shall not exceed the construction pressure class.
2. Total allowable leakage shall not exceed the designed leakage class {specifier shall
determine}.
3. When partial sections of the duct system are tested, the summation of the leakage for
all sections shall not exceed the total allowable leakage.
4. Leaks identified during leakage testing shall be repaired by:
a.
b.
c.
Complete removal of the sealing materials.
Thorough cleaning of the joint surfaces.
Installation of multiple layers of sealing materials.
5. The entire ductwork system shall be tested, excluding connections upstream of the
terminal units (i.e. ductwork shall be capped immediately prior to the terminal units, and
tested as described above).
After testing has proven that ductwork is installed and performs as specified, the terminal
units shall be connected to ductwork and connections sealed with extra care. Contractor
shall inform the Owner when joints may be visually inspected for voids, splits, or improper
sealing of the joints. If any leakage exists in the terminal unit connections/joints after the
systems have been put into service, leaks shall be repaired as specified for other leaks.
Fixed flow measurement devices (i.e. orifice tubes, nozzles, etc.) shall have current
calibration documentation showing that the device was verified to a National Institute Of
Standards and Technology (NIST) standard within the previous five years or as
recommended by the manufacture and be accurate to at least +/- 2% of reading.
Pressure measurement instrumentation (i.e. manometer) shall have current calibration
documentation showing that the device was verified to a NIST standard within the
previous year or as recommended by the manufacture. Instrumentation shall have an
accuracy of at least +/- 2% of reading and have a resolution of 2:1 with respect to the
measured pressure (i.e. resolution of 0.01 measured 0.1).
D.
All Duct Systems at or below 3 in. w.g. (positive or negative) shall be inspected for visible and
audible signs of leakage.
1.
Leaks identified by inspection shall be repaired by:
a.
b.
c.
2.
E.
Complete removal of the sealing materials.
Thorough cleaning of the joint surfaces.
Installation of multiple layers of sealing materials.
Discrepancies found during testing and balancing between duct traverses and
diffuser/grille readings shall result in re-inspection, repair and retest until
discrepancies are eliminated
At the option of the Owner, if documented in writing, Contractor may be allowed to eliminate
testing of terminal units by capping the supply ductwork prior to the terminal units, then
inspecting the connection to the terminal units when complete. The Owner, only if
documented in writing prior to testing may only exercise this option.
END OF SECTION 23 31 00