Diy Foam Insulation Existing Walls Ideas. Polyicynene and polyurethane are about $1.50 per square foot, including labor, if the wall is open, and $2.25 per square foot for existing walls. 2 thread the blower hose into the first hole, and point the nozzle down deep into the wall cavity.
‘the better insulated, the less energy is needed to keep your home at a comfortable temperature,’ says andre kazimierski, ceo of improovy. ‘in a poorly insulated home over time much more money will be spent on heating and. Check the attic, walls, and floors adjacent to an unheated space, like a garage or basement.