How do I know if my basement is insulated?

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
So I've decided I'm going to rip down the walls and insulate the rimjoists and put up a vapour barrier. The basement is going to a living area and it's important that it stays warm during the winter. I was thinking for the rim joists to install 2in extruded foam board and seal it with expanding foam. Then reuse the pink batts and run the plastic vapor barrier from the bottom of the foam boards to the ground. Stapling it to the studs. Is this the best method?
 
The insulators do use the foam board in the rim but they seal it in with some chaulking made just for that.
Our code calls for the exterior wall to be built 1" away from the concrete wall and that gap behind the wall at the top must be firestoped so fire in that wall can't get to the floor above. Depending on what you have for a sill on top of the concrete we intall either a 2x4 or a 2x6 against the sill and then the top plate of the wall goes against that and the space behind the wall is really close to that inch that is needed and the room comes up just as square as the room upstairs. The vapour barrier goes against the studs before the drywall. There are plastic shells to put switches and outlets in for vapour and the barrier is stuck to the floor with acustic sealer.
And the bottom plate does want something under it so it dosn't wick water up, plastic sheeting, sill gasket, tar paper.
 
Last edited:
Well unfortunately the walls are already framed so I can't put anything under the bottom 2x4. So just to be clear the foam board doesn't require a plastic vapor barrier over it correct?
 
That is correct. When we find wood that is sitting on concrete the inspectors or engineers always get us to treat that sill and the bottom of the studs with the same stuff that is in treated lumber to discouge insects going after damp wood. Lumber yards carry the stuff. Any other times they frown on green lumber inside the home but they say the exerier plates are outside the vapour barrier and if we do some on interior walls say just shrug and say do it just not so much.:confused:
 
Well it's darker along the bottom. But it's not mushy. Just about as solid as the rest studs.
 
I would treat it to keep the bugs out. I you do want to change parts of the plate we just cut the studs up about a foot, put in the new plate and sister the studs with 3 ft peices. The outside walls are not structural.
 

Latest posts

Back
Top