Insulating between joists with double brick wall.
I have a 1920s full double brick home, with joists extending directly into the brick. I'm redoing the ceilings in several rooms on the main floor. I've torn out the ceilings, exposing the joists and in turn the brickwork between the wall plaster and the subfloor above.
As expected, now that the ceiling it out, the draft is substantial.
I'm considering cutting stone wool insulation (Roxul R14/R22 or similar) and placing it vertically between each joist, butted up against the brick exterior wall, to cut down on the draft coming in across the upstairs floorboards - the intent being to warm up my 2nd floor floors, which currently have a bit of a breeze running under them.
Is this a bad idea? I've heard that old homes need to 'breathe', but I think that refers more to the space between the double brick wythes, so I think I should be ok.
Last edited by rugby style; 12-20-2010 at 12:22 PM.