During a leisurely stroll through Lowes a week or so ago, Casey and I managed to find ourselves getting ahead of ourselves by looking at foamboard insulation to start insulating the basement. We were just looking — seriously — when we found a deal too good to pass up. Foamboards that were originally $13 per 4×8 sheet were being clearanced out for $3 a sheet. We had no intentions on starting this basement project for a while. However, who can pass up a deal like that? We went home to think about it, and early the next day while I was at work, Casey ran over to buy every last one they had in stock. Fourteen when it was all said and done.

Of course, buying some sheets of foamboard can’t be as simple as buying them, loading them, and bringing them home. No, of course not. She borrowed her parent’s Chevrolet Blazer. Who knew that 4×8 sheets do not fit into a Blazer? So I borrowed my boss’ truck and ran out there to pick them up, when the wind chill was in the -30* range. It isn’t fun tieing sheets down to a truck without gloves when it is that cold outside.

All said and done, we had 14 sheets of foamboard insulation tucked away in our garage.  Now I was on a mission.

First, I moved all my junk away from the walls. It is amazing how much smaller a room gets when you take everything from the sides and put it in the middle. Next, I washed the concrete walls off and put a fan on it to let it dry. Well, before this was done, I had to also remove an outlet that was nailed into the concrete. That is harder to do than you’d think…

Next, I put some foamboard adhesive (yes, that is what it is called) on the back of the foamboard and slapped it onto the concrete. The stuff doesn’t hold well at first, so I pushed some boxes of tile up against the bottom, and used some masking tape to hold the top and side edges down for the night. By morning, it wasn’t going anywhere. As I worked with it more, I realized that in my basement, with the uneven walls, it works better to apply the adhesive to the high points on the concrete rather than to the foamboard as I’m sure that the low areas are never in contact with the foamboard.

Here is the one corner of the room insulated up to the joists:

All-in-all, I’m quite pleased with the method and the result (looks a lot better than the rough 80 year old concrete!).

From here, I will eventually frame up walls against the foamboard and use R11 (possibly R13, depending on if I can hit a sale) between the studs. If you want to learn more about this method, check out Todd’s website, Home Construction Improvement for the intricate details. I bugged Todd a couple times with some questions and he has helped out quite a bit in answering them. Thanks again Todd!