The typical Bordeaux basement
Bordeaux grew around the rail line: brick duplexes from the 1940s and 1950s, narrow yards, party walls hiding cavities that were never filled. 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. The damp smell leaves with the cold surface: plastic stops sticking, cardboard stays dry.
Insulating from inside: the sequence that keeps walls dry
In Bordeaux, low attics under two-slope roofs limit blowing depth: cellulose is calculated per square foot to reach R-40 without smothering the vents. 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. A properly insulated basement sits within a degree or two of the upper floor: the room becomes livable without extra heat.
A storey that holds its own heat
Bordeaux concentrates rear kitchens and upstairs bathrooms: the coldest rooms, exactly where insulation is missing. 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. The damp smell leaves with the cold surface: plastic stops sticking, cardboard stays dry.
Frequently asked questions
Must the Bordeaux 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.