I've got a large unfinished attic that I'm hoping to turn into a master bedroom suite in the next five years, but for now, it's mainly being used for storage. The space is freezing cold with no insulation in the walls, rafters, or ceiling. I'm considering picking up one of those DIY spray foam insulation kits with 12-24 cans and a spray gun to cut down on heat loss, especially since I'm planning to add a ceiling later this year. The walls are open, so I'm thinking I can tackle the insulation project gradually as I move stuff around. But, are these spray foam kits really worth it? I've seen they only reach an R-value of 5-6 at best, which isn't great, but it's better than nothing, right?
3 Answers
It really depends on your situation. These spray foam kits can be effective for air sealing and could fit into a larger insulation project. If you're okay with spending around $400 now, and then potentially $1,500 later on for better materials, then go for it. Just know that it might not be the final fix you're looking for.
Before jumping in, you really need a solid plan. Insulating a half-story or any open space is trickier than most realize. The type and amount of insulation, as well as your framing setup, all play a critical role. You don’t want to find yourself having to redo things later on.
Honestly, I wouldn't recommend going with those DIY spray foam kits. You'll likely get better performance by using foam board or polyiso sheet foam in the stud cavities. Spray foam might not give you the insulation level you need for a permanent solution, especially with future plans for a bedroom.