The typical Ahuntsic basement
In Ahuntsic, brick duplexes built between 1930 and 1960 mostly still hold their original insulation: two or three settled inches, installed before anyone spoke of air barriers. A bare foundation wall lets enough cold through to chill the slab and the first row of flooring above.
Electrical boxes and ducts crossing the envelope get sealed before the walls close. A properly insulated basement sits within a degree or two of the upper floor: the room becomes livable without extra heat.
Insulating from inside: the sequence that keeps walls dry
Ahuntsic's streets open straight to the north-west wind: facades take the full blast from November on. Condensation on cold concrete feeds corner mould: the typical basement smell, cardboard boxes going soft.
From inside, insulation is closed-cell foam: two continuous inches bonded to the concrete, air barrier and vapour barrier in one move. The damp smell leaves with the cold surface: plastic stops sticking, cardboard stays dry.
A storey that holds its own heat
Many Ahuntsic units heat a room above the porch for nothing: a floor over a poorly sealed void, cold even with the thermostat maxed. The Code in force targets R-24 and up for an insulated foundation wall: most 1960s basements offer paneling on furring, nothing more.
The slab perimeter gets a continuous joint: that's where cold bites hardest. A properly insulated basement sits within a degree or two of the upper floor: the room becomes livable without extra heat.
Frequently asked questions
Must the Ahuntsic basement be emptied first?
We clear the perimeter of the walls being treated; the rest of the room can stay, furniture protected under sheeting.
Is foam safe for indoor air?
Certified closed-cell foam is inert once cured, after 24 hours: application happens with ventilation running through the day.
Insulate before or after crack repair?
Always after: insulating over a moving foundation wall hides the symptom. Crack repair precedes insulation.