View Full Version : Insulating Finished Basement
09-10-2008, 06:00 PM
I live in upstate NY (cold in winter) and I am wondering what to do about insulating my basement before framing walls.
My house is 10 years old and has bat fiberglass insulation covering about the top 75% off the wall.
I was thinking about just gluing rigid insulation on the bottom uninsulated part and framing up an inch clear of the bats for ventilation.
My other option is to rip it down, and glue rigid insulation the entire way before I frame (reusing the insulation else where in the house)
Or should I just leaving it "as is" and framing up. I mean, it is like 90" below grade and there is no draft.
What have people done in their basements?
P.S. I am going to redo the rim joists with rigid insulation sealed with foam before I frame up.
09-10-2008, 06:10 PM
Check out BuildingScience.com. They have some good information on properly insulating a basement.
09-11-2008, 07:11 PM
Yeah. I have seen that before. Basically recommends that you fix XPS everywhere and tape it up.
I have a floating slab (not for soil movement) with a 3/4" gap around the perimiter which connects to a drain which discharges into a sump pump (pretty standard up here)
It seems like I need to keep that clear to let any water drain down there. I have never had moisture problems.
09-12-2008, 06:23 AM
I was watching home improvement show based in canada. This was done during the winter. He basically framed in the outside walls and sprayed insulation there. He also put in a subfloor with a layer of insulation below that.
09-12-2008, 06:35 PM
I think I found the best system for an interior perimeter drain, but what is the "spacer mesh" that is supposed to go between the foundation wall, and the rigid insulation?
By the way, this appears to the the only situation where you can use foil fronted, fire rated, rigid insulation for a basement. The reason is that there is no need for the water to transpire through the insulation. It has a path to the interior drain.
Also, I have drainage tile pipes, which are not pictured in the drawing.
"I was watching home improvement show based in canada. This was done during the winter. He basically framed in the outside walls and sprayed insulation there. He also put in a subfloor with a layer of insulation below that. "
Did you notice the beaty of his system was that the wall was framed with a gap between the 2x4s and the wall? When they sprayed the insulation they filled this gap so there is no transfer of heat from the wall to the frame (well, little anyway)
09-13-2008, 08:31 AM
I will no remove the old insulation due to the amount of fiber glass you will spread around the whole house.
Before you insulate and put up your additional insulation, do not forget to check and fix for any cracks and water seepage. Now is the time!
I found a good article at http://handyowner.com on how to go about checking for and fixing basement water leaks (http://handyowner.com/2008/07/13/repair-basement-water-leak/)