The Ontario Building Code | Insulation and Coverings
6.2.9.2. insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation and Coverings
(1) insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation and coverings on pipes shall be composed of material suitable for the operating temperature of the system to withstand deterioration from softening, melting, mildew and mould.
(2) insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation and coverings on pipes in which the temperature of the fluid exceeds 120°C,
(a) shall be made of noncombustible material, or
(b) shall not flame, glow, smoulder or smoke when tested in accordance with ASTM C411, "Hot-surface Performance of High-temperature Thermal insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation", at the maximum temperature to which such insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation or covering is to be exposed in service.
(3) Except as provided in Sentence (7), where combustibleinsulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation is used on piping in a horizontal or vertical service space, the insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation and coverings on such pipes shall have a flame-spread ratingthroughout the material of not more than 25 in buildingsof noncombustible construction and not more than 75 in buildings of combustible construction.
(4) Except as provided in Sentence (7), insulation and coverings on piping located in rooms and spaces other than the service spaces described in Sentence (3) shall have a flame-spread rating of not more than that required for the interior finish for the ceiling of the room or space.
(5) Except as provided in Sentence (7), where combustibleinsulation and covering is used on piping in buildingsdescribed in Subsection 3.2.6., they shall have a smoke developed classification of not more than 100.
(6) Exposed piping or equipment subject to human contact shall be insulated so that the temperature of the exposed surface does not exceed 70°C.
(7) No flame-spread rating or smoke developed classification limitations are required where combustibleinsulation and coverings are used on piping when such piping is,
(a) located within a concealed space in a wall,
(b) located in a floor slab, or
(c) enclosed in a noncombustible raceway or conduit.
In Plain Language
This clause covers insulation wrapped around mechanical piping, not attic or wall insulation. It sets rules for material choice, fire safety ratings, and surface temperature limits. Insulation on hot piping has to resist heat without degrading, and once pipe temperatures pass 120°C the insulation generally has to be noncombustible or pass a specific hot-surface flame test. Combustible insulation in service shafts or exposed rooms is limited by flame-spread and smoke ratings tied to the building's construction type, and exposed pipes people could touch must stay at or below 70°C on the surface.
Common Questions
Q: Does this clause apply to attic or wall insulation?
No. This article covers insulation and coverings applied to mechanical piping, not building envelope insulation, which is covered elsewhere in the Code.
Q: Why do exposed pipes need insulation even if they're not extremely hot?
Sentence (6) requires exposed piping that people could touch to be insulated so the surface temperature stays at or below 70°C, to prevent burns, separate from the fire-safety insulation requirements in the rest of the article.
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.