OLD HOME - Insulbrick with stud infill insulation

[srahome]

All,

New to this resource - finding lots of great things. I recently bought an old house (circa 1914) in Toronto, Canada and the west and south facing walls are clad in insulbrick.

I cut a huge hole in the back (west wall) for a new slider to the back yard. The framing around the rough opening was done in 2x4 with batt insulation and interior vapour barrier (VB). The surrounding wall is plaster (not lath but cement board with hand plaster finish) with cotton (?) insulation in the stud space.

I understand from some other posts that the insulbrick on the exterior may be a VB, resulting in condensation within the cotton insulation. Will I have problem with the new VB I installed around the new slider? I know a double VB is bad.

I was also planning on cladding the insulbrick parts of the house with new siding (pre-finished wood) and thought of wrapping the house in Tyvek (over the insulbrick) before strapping and siding goes on. Any thoughts?

Thanks for the advice.

Cheers

[danh]

Yes a double VB is a bad thing. Don't fool yourself. There are no watertight structures - focus on drying ability.

Second, you need to keep the inside face of the insulbrick above problem temperatures (usually about 45 oF in a typical house). ANd to do this, you need to eliminate the cotton insulation.