Insulation Retrofit Choices for Brick or Block Masonry Wall Cavities
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What foam insulation would work for insulation retrofit on a brick and block building wall?
Is it proper to insulate the air space between brick wythes or between brick and block structure of a masonry wall?
Adding insulation to a brick or block masonry building wall
Insulation advice for interior walls
Questions & answers about retrofit insulation for brick or concrete block building walls
Brick or block masonry wall insulation retrofit: this article describes procedures and materials for the insulation retrofit for a brick or block masonry wall cavity.
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How Add Insulation to Brick or Block Masonry Wall Cavities
The accompanying text is reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss. Our page top photo shows the Sheffield Stable in Saugerties, NY when we inspected it in 2005. This structural brick building was uninsulated and under consideration for restoration.
The question-and-answer article about insulating a masonry wall using foam, quotes-from, updates, and comments an original article from Solar Age Magazine and written by Steven Bliss.
What Foam Insulation is Best for Retrofitting the Cavity in a Brick-and-Block Wall?
Question:
What foam insulation would be appropriate for retrofitting the cavity in a brick and block masonry wall?
How about a 1980's product called Dacotherm, which I heard about a couple of years ago?
- Blair Pollock, Integrated Energy Systems, Chapel Hill NC
Answer:
According to Jerry Carrier, an engineer at the Brick Institute of America in McLean VA, the 1-inch cavity between the brick and the blocks should not be filled with any type of insulation. That space is there to let any moisture that gets into the wall drain out.
If you fill the air space between brick wythes or between a brick veneer and a structural block wall, moisture may be trapped within the wall.
In a freezing climate moisture trapped in a masonry wall can lead to serious structural damage from frost.
Mike Ondra, a designer with the Shelter Design Group, Stoney Run PA, said that although he had heard of some retrofits where the 1-inch cavity in the masonry wall was foamed full of urethane insulation (in the 1970's or 1980's), he had never tried it himself.
Ondra preferred (in a 1985 interview) to stud up an interior 2x3 wall and fill that cavity with foam insulation. The stud wall is build one-inch out from the masonry wall to ensure that the foam forms an uninterrupted thermal break with the outdoor-exposed masonry wall.
Another option is to nail the ties directly to the studs between each 24-inch course of rigid insulation board glued to the interior surface of the masonry wall [discussed at BRICK VENEER WALL INSULATION].
Solar Age also contacted Diamond Shamrock (Irving TX), the manufacturers of Dacotherm, a loose-fill inert silicate material. They do not recommend the use of Dacotherm in block walls. Dacotherm is biodegradable. If it gets wet it breaks down. It is suitable for dry locations.
Our foam insulation photograph (above) shows testing for air leaks at voids in a spray-applied icynene foam insulation retrofit project.
Here we include solar energy, solar heating, solar hot water, and related building energy efficiency improvement articles reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.
The link to the original Q&A article in PDF form immediately below is preceded by an expanded/updated online version of this article.
Q & A: How to add Insulation in a Brick or Block Wall: Insulating a Brick Cavity - PDF version, use your browser's back button to return to this page
Questions & Answers regarding this article
Questions & answers about retrofit insulation for brick or concrete block building walls
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Solar Age Magazine was the official publication of the American Solar Energy Society. The contemporary solar energy magazine associated with the Society is Solar Today. "Established in 1954, the nonprofit American Solar Energy Society (ASES) is the nation's leading association of solar professionals & advocates. Our mission is to inspire an era of energy innovation and speed the transition to a sustainable energy economy. We advance education, research and policy. Leading for more than 50 years.
ASES leads national efforts to increase the use of solar energy, energy efficiency and other sustainable technologies in the U.S. We publish the award-winning SOLAR TODAY magazine, organize and present the ASES National Solar Conference and lead the ASES National Solar Tour – the largest grassroots solar event in the world."
Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education.
Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com.
Excerpts with updates and annotations expanding the original Best Practices Guide text can be found in the online review and book summary at BEST CONSTRUCTION PRACTICES GUIDE and also at DECK & PORCH CONSTRUCTION, at INDOOR AIR QUALITY IMPROVEMENT GUIDE, and in other articles found at InspectAPedia.com such as HOUSEWRAP AIR & VAPOR BARRIERS, SOUND CONTROL in BUILDINGS, and other topics.
Arlene Puentes is a licensed home inspector, past chapter president of the Hudson Valley chapter of the American Society of Home Inspectors, an educator, and building failures researcher in Kingston, NY. Contact Arlene Puentes at: ap@octoberhome.htm or at 845-339-7984.
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