insulation

September 26, 2009 7:27 AM

Outside facing wall insulation?

I have an exterior wall that is currently without insulation. I won't likely get drywall up before winter -- and I want to replace the windows anyways. With that in mind, what should I do to insulate the walls? Standard roll-in insulation?

posted by SirStan to home & garden (4 comments total)

You could put in the insulation and cover it with plastic vapour barrier and tape it around the corners and existing window. Keep in mind that the plastic is a fire hazard until you cover it with drywall.
posted by bonobothegreat at 7:37 AM on September 26

In your climate bonobothegreat has the basics. I don't know what roll in insulation is, here fibreglass comes in discrete batts. They need to be covered with a vapour barrier both to prevent internal condensation and to keep them from spreading teeny glass shards everywhere. At 8100 degree days annually if your wall is less than 2X6 I'd sheath the interior XPS ridgid sheets, say 1", to bring the R value of the assembly up and to provide a thermal break over the studs.

Vapour barrier plastic is relatively delicate stuff. It is was me I'd buy some gyproc now and install a strip by setting full sheets on top of your electical boxes. Only put a few screws in each sheet. This will cover the vapour barrier from about 16" to 64" above the floor which is where people will bump into the wall. And because you are above the boxes you'd have to do minimal cutting around projections. When it comes time to replace the windows just unscrew the gyproc and it is ready to be used normally.
posted by Mitheral at 10:25 AM on September 26

I don't know what the costs are, but that spray-in insulation seems like the bomb. It sprays on as a liquid and expands into every crevice and cranny. When it's dry, you slice off the excess and put up the drywall. It seems like the best way to do it. But I also hate fiberglass.
posted by gjc at 9:28 PM on September 26

DIY spray in foam runs around $335 for 13 cu. ft. or $3 a board foot. Very cool, quite expensive.
posted by Mitheral at 10:08 PM on September 26