Table Source: NBC of Canada 2015

9.25.5.2.(1) Sheet and panel-type materials described in Article 9.25.5.1. shall be installed

a) on the warm face of the assembly

b) at a location where the ratio between the total thermal resistance of all materials outboard of its innermost impermeable surface and the total thermal resistance of all materials inboard of that surface is not less than that required by Table 9.25.5.2., or

c) outboard of an air space that is vented to the outdoors.

9.25.5.2.(2) For walls, the air space described in Clause (1)(c) shall be drained and ventilated and shall be not less than 10 mm deep behind the cladding, over the full height and width of the wall.