Roof Insulation Toronto

Flat Roofs Are Everywhere Here

Row houses, semis with rear additions, low-rise commercial and a great deal of infill all carry flat or near-flat roofs, and none of them has an attic to fill. The insulation lives in the roof assembly itself, which means the questions are about the deck, the existing membrane and where vapour control sits — not about how many inches to blow onto a floor.

Vaulted Ceilings and Third-Storey Conversions

A vaulted ceiling has no attic above it, so the insulation has to fit the rafter cavity, and in older Toronto houses that cavity is usually shallower than the R-value would like. Closed cell foam delivers more R per inch than anything else that fits and air seals the assembly at the same time, which matters because there is no buffer space between the room and the cold deck.

Ventilation Changes When a Roof Is Sealed

A vented roof assembly relies on airflow between the insulation and the deck to carry moisture away. Sealing the deck with foam removes that airflow by design — the assembly becomes unvented and the foam manages vapour. That is a deliberate change, not a side effect, and it should be explained before the work rather than discovered afterwards.

Foam Is Insulation, Not a Membrane

Closed cell foam resists bulk water and does not absorb it the way fibrous insulation does, but it is not a roofing membrane and must never be treated as one. The roof surface above still does the job of keeping water out. Anyone implying otherwise is overselling the product.