The Ontario Building Code | Tape
6.2.4.9. Tape
(1) Tape used for sealing joints in air ducts, plenums and other parts of air duct systems shall meet the flame-resistance requirements for fabric in CAN/ulc-S109, "Flame Tests of Flame-Resistant Fabrics and Films".
In Plain Language
Tape used for sealing joints in residential air ducts must meet the same flame-resistance requirements for fabric under the referenced CAN/ULC standard used throughout the Code's duct provisions.
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.