The Ontario Building Code | Lining or Backing
6.2.8.1. Lining or Backing
(1) Every steam or hot water radiator and convector located in a recess or concealed space or attached to the face of a wall of combustible constructionshall be provided with a noncombustible lining or backing.
(2) Every steam or hot water radiator and convector shall be installed to conform to the clearance requirements of Table 6.2.9.3.
6.2.9. Piping for Heating and Cooling Systems
In Plain Language
Every steam or hot water radiator and convector located in a recess, concealed space, or attached to a combustible wall must be provided with a noncombustible lining or backing, protecting the adjacent combustible construction from heat damage.
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.