The Ontario Building Code | Fire Blocks between Nailing and Supporting Elements

3.1.11.3. Fire Blocks between Nailing and supporting Elements

(1) In a building required to be of noncombustible construction, a concealed space in which there is an exposed ceiling finish with a flame-spread rating more than 25, shall be provided with fire blocks conforming to Article 3.1.11.7. between wood nailing elements, so that the maximum area of the concealed space is not more than 2 m².

(2) In a building required to be of noncombustible construction, fire blocks conforming to Article 3.1.11.7. shall be provided in the concealed spaces created by the wood members permitted by Sentence 3.1.5.8.(2), so that the maximum area of a concealed space is not more than 10 m².