The Ontario Building Code | Cold Weather Requirements

9.3.1.9. Cold Weather Requirements

(1) When the air temperature is below 5°C , concrete shall be,

(a) kept at a temperature of not less than 10°C or more than 25°C while being mixed and placed, and

(b) maintained at a temperature of not less than 10°C for 72 h after placing.

(2) No frozen material or ice shall be used in concrete described in Sentence (1).

9.3.2. Lumber and wood Products