The Ontario Building Code | Clearances of Ducts and Plenums
6.2.3.19. Clearances of Ducts and Plenums
(1) The clearances from combustible material and supply plenums, supply ducts, boots and register boxes of heating systems shall conform to the requirements of Subsection 6.2.4.
In Plain Language
Clearances between combustible material and heating system supply plenums, ducts, boots, and register boxes must meet minimum distances preventing heat transfer from igniting nearby combustible building materials.
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.