The Ontario Building Code | Required Resistance to Heat Transfer
184.108.40.206. Required Resistance to Heat Transfer
(1) Except as provided in Sentence (2), where a buildingcomponent or assembly will be subjected to an intended temperature differential, the component or assembly shall include materials to resist heat transfer or means to dissipate transferred heat in accordance with this Subsection.
(2) The installation of materials to resist heat transfer in accordance with this Subsection is not required where it can be shown that uncontrolled heat transfer will not adversely affect any of,
(a) the health or safety of building users,
(b) the intended use of the building, or
(c) the operation of building services.