The Ontario Building Code | Insulation Materials
9.25.2.2. Insulation Materials
(1) Except as required in Sentence (2), thermal insulation shall conform to the requirements of,
(a) CAN/CGSB-51.25-M, "Thermal Insulation, Phenolic, Faced",
(b) CGSB 51-GP-27M, "Thermal Insulation, Polystyrene, Loose Fill",
(c) CAN/ULC-S701, "Thermal Insulation, Polystyrene, Boards and Pipe Covering",
(d) CAN/ULC-S702 "Mineral Fibre Thermal Insulation for Buildings",
(e) CAN/ULC-S703, "Cellulose Fibre Insulation (CFI) for Buildings",
(f) CAN/ULC-S704, "Thermal Insulation, Polyurethane and Polyisocyanurate, Boards, Faced",
(g) CAN/ULC-S705.1, "Thermal Insulation – Spray Applied Rigid Polyurethane Foam, Medium Density – Material – Specification", or
(h) CAN/ULC-S706, "Wood Fibre Thermal Insulation for Buildings".
(2) Theflame-spread rating requirements contained in the standards listed in Sentence (1) shall not apply.
(3) Insulation in contact with the ground shall be inert to the action of soil and water and be such that its insulative properties are not significantly reduced by moisture.
(4) Type 1 expanded polystyrene insulation as described in CAN/ULC-S701, "Thermal Insulation, Polystyrene, Boards and Pipe Covering", shall not be used as roof insulation applied above the roofing membrane.
In Plain Language
Insulation materials must conform to the standards referenced in this article, ensuring consistent thermal performance and quality across different products.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.