**184.108.40.206. Protection of Foamed Plastics **
Except as provided in Sentence (2), foamed plastics that form part of a wall or ceiling assembly in *combustible construction *shall be protected from adjacent space in the building other than adjacent concealed spaces within attic or roof spaces, crawl spaces, and wall assemblies, by,
(a) one of the finishes described in Subsections 9.29.4. to 9.29.9.,
(b) sheet metal mechanically fastened to the supporting assembly independent of the insulation and having a thickness of not less than 0.38 mm and a melting point not below 650°C provided the building does not contain a Group C major occupancy, or
© any thermal barrier that meets the requirements of Clause 220.127.116.11.(2)(e).
18.104.22.168. Heated and Unheated Crawl Spaces
Crawl spaces shall be considered to be heated where the space,
(a) is used as a hot air plenum,
(b) contains heating ducts or heating pipes that are not sealed and insulated to minimize heat loss to the space, or
© is not separated from heated space in accordance with Section 9.25.
Heating of heated crawl spaces shall conform to Section 9.33.
Insulation, an *air barrier system *and a *vapour barrier *shall be installed in the walls of heated crawl spaces in accordance with Section 9.25.