Rigid Foam Installation - glue or...?

[myopposablethumb]

Hi. The exterior walls of my house are solid brick and plaster (no insulation). I live in Utah where the summers are hot and winters are cold. In the winter the exterior walls are bone-chilling cold, and in summer the exterior walls act like an oven radiating stored heat into the house.

I'm doing some remodeling and I'd like to put 2" of rigid foam insulation on the exterior walls. I realize this isn't going to make a huge difference in the comfort of the house, but R10 is better than no insulation at all.

I was also considering framing the exterior walls with 2x4 and using regular fiberglass or blown insulation, but the house is already quite small and I don't want to make the rooms any smaller...

My question is, can I use the adhesive to glue the foam panels directly onto the plaster on the interior walls or do I need to attach 2" furring strips onto the walls (16" O.C.) and put foam between the furring strips?

My main concerns about gluing the panels is how well they will stick to the plaster (which is covered with wallpaper and paint), and how well the drywall will stick glued to the rigid foam...?

Any advice?

Thanks, Daniel.

[pushkins]

If you plan to glue the panels directly to the plaster, are you planning on adding a layer of drywall over the insulation sheets ?

[myopposablethumb]

Hi Pushkins,

If I've understood your question correctly, yes, I was planning on hanging drywall over the insulation. If I don't use the furring strips then I presume I will have to glue the drywall directly onto the foam.

I've had glued drywall before, but on wood studs not foam.

Any thoughts about the finish?

Thanks, Daniel.

[pushkins]

You would be best advised not to glue drywall to foam insulation board. Almost certainly the bond between drywall and foam will fail within a short period of time.
You probably would be better suited to cutting a small hole (3" diameter)in the top of each stud cavity and filling the voids with fiberglass blow in insulation.

[mrcaptainbob]

drywall/brick....

Are you telling us the original dry wall is bonded directly to your outside brick?

[pushkins]

I think th OP was trying not to remove the original lathe and plaster and add a layer of insulation over the top of it.
It wouldn't be a good idea in my opinion, I'd be renting a pump from Lowe's and pump in the new Pink fiberglass insulation, easier to repair a 3" hole.