Your turn: We love our house but hate the electric bills. I always thought that foam insulation on the attic roof inside would help but others disagree.
We have a gigantic roof with lots of space and lots of hot air. Would this help and what could we expect to pay? We would like to do it ourselves if possible.
The base house is 2400 sq with vaulted and trey ceilings & 9 ft ceilings everywhere else. The bonus room is 480 sq over a garage (not well insulated between garage and bonus). Thanks for your thoughts.- Jill
My Turn: You are right to suspect that your roof factors into your high electric bills. Here’s why…. As much as 40% of your home’s total energy leaks out of a typical house. Much of it can escape through your ceilings and ‘gigantic’ attic.
I think your house (at least the main attic) could benefit from foam insulation. The biggest advantage of foaming is its ability to form a continuous layer as well as seal cracks and seams. It’s typically four to five inches thick and contains tiny bubbles resembling angel food cake. This interrupts continuous air flow but still ‘breaths microscopically’ so the roof sheathing stays healthy. I can’t think of any other types of insulation that can do this as well.
Installing whole house foam insulation isn’t a Do-It-Yourself project because of the required safety equipment and chemicals. Best to hire a qualified contractor. Costs vary regionally but I’ve found about $2/roof sq. ft. is good for budgeting.
By foaming you get extra bonuses too. Any attic-installed mechanical systems should work more effectively because the foam blocks solar radiant heat drilling inside. Your attic temperature that was about 140 degrees drops considerably and that extends the life of your system. You’ll also find it quieter because foam has sound proofing properties.
Your bonus room is another story. Likely the ceiling above it was insulated before the interior sheetrock was hung and now there’s no way to easily access the inside roof deck.
The attic behind the side walls; however, could be foamed. I think you’d still benefit with a partial refit approach even though only part of the space is foamed.
You might benefit from a radiant barrier on the other portion. See taming solar heat on and under your roof in My “Sneaky Solar Strategies That Pay” e Book or video.