Prepping for Spray Foam
Getting ready for a foam-insulation crew means doing a lot more than you’d think.
Synopsis: Installing spray-foam insulation is all about the prep work. Because North Carolina builder and designer Michael Chandler has been using spray-foam insulation in all the houses he has built for the past four years, he has learned to navigate the process. His first order of business usually involves getting clearance from building officials and inspectors, who sometimes are unfamiliar with the spray-foam process and might have concerns about ventilation and fire safety. Next, he installs extra backing and blocking to get the framing ready for the spray-foam installation. Because the spray foam sticks to everything, Chandler keeps plenty of crew members and drop cloths available to monitor the installation. Chandler suggests checking the foam with a depth gauge to make sure that the proper amount of foam has been installed. Finally, he advises that a spray-foam installation may require the use of a trailer-mounted generator.
Spray-foam insulation is gaining popularity these days, and for good reason. Not only does it offer lots of R-value per inch, but it also air-seals the house. I’ve been building custom homes in North Carolina for more than 20 years, and I’ve been using spray-foam insulation for the past four. These days, all my projects get 8 in. to 12 in. of foam under the roof deck, and I often use foam to insulate walls and crawlspaces as well.
Prepping for the spray-foam crew is now just another part of the building process, but it took some time and a lot of stained shingles and concrete for me to figure out the learning curve. Along the way, I discovered that the first hurdle in using spray-foam insulation might just be working with the building inspector.
Venting, fire safety, and building officials
The first time I insulated an attic with spray foam, the building inspector asked…