Basement Insulation

raulakh

Hello Everyone,

I am installing the insulation roxul (R-14) into 2by4 studs in my basement walls.
I kept my frames 1.5 inch away from the basement concrete walls. I didn't removed the insulation done by my builder which covers only half the height of the concrete walls dropping from ceiling, instead I left it behind the studs alongwith vapour barrier done by builder.

Now when I am installing the insulation I always have a 1 inch or more empty space left after applying insulation specially lower part of the wall which was not insulated by the builder. In upper part there is no problem because the empty space behind the studs is occupied by previous insulation by the builder.
What Should I do. If I am applying 2nd layer it looks little tight and comes out from studs. Or Is it a good idea to decrease the thicness of second layer according to the space left in studs. I am just worried If I applied the vapour barrier on the empty space, the air left inside the studs may hurt my insulation in future.
Sorry for lengthy question.

Thank-you
Randy
Hamilton, Canada

ccarlisle

Personally, I like starting with a clean slate and by that I mean I like taking everything off before I put my work back onto a basement wall. I don't know what your builder put on the wall, maybe something like 1" of polystyrene, but in any case, the old vapour barrier has to come off - you can't have 2 vbs down there.

In your shoes, I would remove the old stuff, put my straight and true stud wall an inch or so away from the concrete wall, put down a roll of 4" wide foam underneath the bottom plate, use the Roxul to fill in the void completely, then staple a 6mil plastic vb, well taped and sealed with acoustic sealant, right from the bottom plate to the top, not forgetting the spaces between the upper joists. Then cover that with 1/2" drywall...

Remember up here we're in the 'freezing zones' and what we need up here is quite different than what others need in other zones.

raulakh

Thank-you CCarlisle