I have approximatly 1,100 sq. ft. of unfinished basement. I am lucky that it is both dry and radon free. I use the majority of it for laundry and storage, and then the rest of it is my workout room. I am planning out finishing the walls over the next year or so, but I started with a basic, and smart project, insulating the rim joists. When I bought the house all of the rim joists had R-13 fiberglass insulation stuffed in, which is better than nothing, but not really ideal anymore. Here is what I am working with:
A shot of the workout room wall
The old insulation
Insulation removed
Look at the dark stains on the fiberglass, that is all from airflow coming through the rim joists into the house
I cleaned up each opening, cut the 9.5 x 14.5 pieces of R-10, 2" thick rigid foam out for each one, and then used Great Stuff spray form to seal around the edges. The final result is an air-tight seal that will keep any outside air from entering the basement walls via the rim joists. I can now put in fiberglass insulation over these openings once I finish the walls. I will likely do R-13, but R-19 is another option.
I did one wall so far, so 5 walls to go.
My future plans are 2" rigid foam on the exterior walls, followed up by a traditional 2x4 stud wall to run electrical and drywall. It will make the space approximately 6" smaller on each wall, but it should be a much cozier space. :tup:
Are you going to place the rigid foam on the wall, leave a gap, or use a vapor barrier?
Good stuff so far. I removed the R13 from my basement this summer, and haven’t replaced it yet. Did you use anything but the spray foam to hold the foam board in?
Doing my rim joist as well, I am buying a 2 part spray foam that covers 600 linear feet. Air tight, easier then cutting foam. Did you look into that at all?
I only used the spray foam to hold in the board. I cut them to size within 1/8", so most of them I had to pound in to get into the space. The foam definitely tightened up the few that went in loose though. They are all solid and sturdy now.
I am going to put 2" rigid foam on the wall as well. I am not using a vapor barrier or leaving a gap. I am using this 2x4 wall method, sans the extra fiberglass insulation between the studs:
I can’t think of the measurement at the moment. It is less than 8’, but more than 7’. I can do jumping jacks down there when I work out, but I have to be careful to not hit my fingers.
I did, but this will do the same job, at way cheaper. I can do my entire basement for around $100 with this method. It is a ton of work cutting out all of the slightly different sizes though, and there are a few openings that have wiring, ducting, etc…, so if you have the money to spend, the spray foam is probably a way better option.
