Understanding the insulation used in the Ultra Air Barrier Wall System

Words: Doug ToddWith the Ultra Air Barrier Wall System from Dow Building Solutions, masonry contractors now have a system that can be easily installed and keeps more of the contract under the mason’s control. In the past, contractors often installed a separate air barrier then covered it with insulation. With the Ultra Air Barrier Wall System, contractors now have a proven, easy-to-install and economical system that combines a continuous, high R-value rigid insulation AND an air/vapor-barrier for brick and block cavity wall. With fewer installation steps than standard construction methods, the Ultra Air Barrier Wall System provides a competitive advantage.

The Ultra Air Barrier Wall System delivers exceptional long-term thermal insulating performance and excellent air/vapor-barrier properties in brick and block walls using trusted and familiar products: STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation and GREAT STUFF PRO™ Gaps & Cracks Insulating Foam Sealant.*

For more information, here are the links to:
In this feature article, the focus is on the insulating component: STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation.

Getting the Most from the Insulation

Most contractors are familiar with the traditional ‘blue’ STYROFOAM™ Brand extruded polystyrene foam insulation. After all, it has been around for over 60 years. However, about 10 years ago, Dow Building Solutions introduced a new ‘black’ product - STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation. Also an extruded polystyrene insulation, this enhanced product uses a patented carbon black material to increase thermal performance by reducing infrared radiation transmission and lowering heat flow. The result is a higher R-value (R 5.6(1) for 1”) versus other extruded polystyrene foam insulations.

Available in 15 ¾” board widths, the square edge insulation easily fits between the wall ties and can accommodate slight imperfections in the tie placement. As an added bonus for contractors, less time is needed to adjust ties up and down when installing the insulation.

Nominal Board Thickness(2) (inches) R-value(1) Board Size (inches)
1.75 10 15 ¾ x 96
2.125 12.0 15 ¾ x 96
2.5 14.0 15 ¾ x 96
3.0 16.8 15 ¾ x 96

STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation at a Glance:
  • High R-value of 5.6 for 1”(1), the highest of all STYROFOAM™ Brand Extruded Polystyrene Foam Insulation products.
  • Long-term performance; resists moisture over time.
  • Consistent thickness; delivers stated thermal performance and optimizes cavity air space effectiveness.
  • Available in thicknesses up to 3”(2).
  • High compressive strength; durable on the worksite.
  • Easy-to-detail (e.g., uses common building practices, tools and equipment.)
  • Versatile; use in load-bearing and non-load bearing walls and in block-backed and steel stud cavity wall applications.
/Public/News/understanding-the-insulation-used-in-the-ultra-air-barrier-wall-system-2.jpg" width="600" height="338" border="0" alt="STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation provides a number of special characteristics and advantages." />
STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation provides a number of special characteristics and advantages.

Properties that Stand the Test of Time

This closed cell structure of STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation provides a number of special characteristics and advantages, including high, long-term thermal performance, high compressive strength and low water absorption — all desired properties of an insulation used in wall assemblies such as the Ultra Air Barrier Wall System.

Property and test method Value
Thermal Resistance per in. ASTM C518, ft2 •h•°F/Btu, R-value, min(1) 1.75" 2.125" 2.5" 3.0"
@ 75 °F mean temp. 10.0 12.0 14.0 16.8
@ 40 °F mean temp. 10.8 13.0 15.0 18.0
@ 25 °F mean temp. 11.12 13.4 15.8 18.9
Compressive Strength, ASTM D1621, psi, min. (3) 25
Water Absorption, ASTM C272, % by volume, max. 0.3
Water Vapor Permeance, ASTM E96, perm, max. 1.75" 2.125" 2.5" 3.0"
1.1 0.9 0.8 0.8
Maximum Use Temperature, °F 165
Coefficient of Linear Thermal Expansion, ASTM D696, in/in •°F 3.5 x 10 -5
Flexural Strength, ASTM C203, psi, min. 50

Click here for Product Specification Sheet.

Working with STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation

The foam insulation is easy to work with in the field, requiring no special equipment or tools. Just measure, cut and install using the installation procedures.

When storing STYROFOAM™ Brand CAVITYMATE™ Ultra insulation, follow these simple guidelines:
  • Do not leave insulation exposed to direct sunlight for more than 90 days. Prolonged exposure to ultraviolet radiation may cause the surface to become faded and dusty. The surface degradation will have no measurable effect on the insulating value of the insulation unless the deterioration is allowed to continue until actual foam thickness is lost.
  • If there is a layer of dust on the insulation, brush it off as the dust could impair performance of any adhesives and finishes used.
  • Use a light-colored, opaque protective covering if excessive solar exposure is expected.
  • When stored outdoors, keep insulation boards tarped or covered to protect from weather and weighted down to prevent boards from being blown around by the wind.
  • Store above standing water.

Helping you be Successful with Dow Support Tools

Dow is committed to helping masonry contractors specify and install this two-in-one system of continuous insulation and air barrier. There are a number of support tools, including:
Still can’t find what you need? Contact us.

Final Thoughts

Let the combination of STYROFOAM™ Brand CAVITYMATE™ Ultra Insulation and GREAT STUFF PRO™ Gaps & Cracks Insulating Foam Sealant - as well as other Dow products - work for you and deliver a winner.

The Ultra Air Barrier Wall System delivers an easy-to-install, cost-effective solution to meet code requirements for continuous insulation and air barriers in one simple solution. Learn more at www.ultrawallsystem.com or call us at 1-866-583-BLUE (2583).

(1) R means resistance to heat flow. The higher the R-value, the greater the insulating power. R-values are expressed in ft2- h-°F/Btu. R-value determined by ASTM C518.
(2) Not all product sizes are available in all regions.
(3) Vertical compressive strength is measured at 10% deformation (5% for STYROFOAM™ Brand PLAZAMATE™ Insulation and for STYROFOAM™ Brand HIGHLOAD 40, 60, and 100 Insulation products) or at yield, whichever occurs first. Since STYROFOAM™ Brand Extruded Polystyrene Foams are visco-elastic materials, adequate design safety factors should be used to prevent long-term creep. For static loads, 3:1 is suggested. For dynamic loads, 5:1 is suggested.

*Read the label and Material Safety Data Sheet carefully before use.
®™* Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow

NOTICE: No freedom from any patent owned by Dow or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer’s use and for ensuring that Customer’s workplace and disposal practices are in compliance with applicable laws and other government enactments. The product shown in this literature may not be available for sale and/or available in all geographies where Dow is represented. The claims made may not have been approved for use in all countries or regions. Dow assumes no obligation or liability for the information in this document. References to “Dow” or the “Company” mean the Dow legal entity selling the products to Customer unless otherwise expressly noted. NO EXPRESS WARRANTIES ARE GIVEN EXCEPT FOR ANY APPLICABLE WRITTEN WARRANTIES SPECIFICALLY PROVIDED BY DOW. ALL IMPLIED WARRANTIES INCLUDING THOSE OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.

STYROFOAM™ Brand Extruded Polystyrene Foam Insulation

CAUTION: This product is combustible and shall only be used as specified by the local building code with respect to flame spread classification and to the use of a suitable thermal barrier. For more information, consult Material Safety Data Sheet (MSDS), call Dow at 1-866-583-BLUE (2583) or contact your local building inspector. In an emergency, call 1-989-636-4400.

WARNING: Rigid foam insulation does not constitute a working walkable surface or qualify as a fall protection product.

Dow Polyurethane Foam Insulation and Sealants

CAUTION: When cured, these products are combustible and will burn if exposed to open flame or sparks from high-energy sources. Do not expose to temperatures above 240ºF. For more information, consult MSDS, call Dow at 1-866-583-BLUE (2583) or contact your local building inspector. In an emergency, call 1-989-636-4400.

GREAT STUFF PRO™ Insulating Foam Sealants contain isocyanate and a flammable blowing agent. Read the label and MSDS carefully before use. Eliminate all sources of ignition before use. Wear long sleeves, gloves, and safety glasses or goggles. Provide adequate ventilation or wear proper respiratory protection. Contents under pressure.

GREAT STUFF PRO™ Gun Cleaner is flammable and contains acetone and propane. Read the label and MSDS carefully before use. Eliminate all sources of ignition before use. Wear gloves, and goggles or safety glasses. Provide adequate ventilation or wear proper respiratory protection. Contents under pressure.
Building and/or construction practices unrelated to building materials could greatly affect moisture and the potential for mold formation. No material supplier including Dow can give assurance that mold will not develop in any specific system.
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