Masonry Construction in Cold Weather

Cold weather can have a significant impact on masonry construction projects. This article discusses the effects of cold temperatures on cement-based materials such as mortar and grout, and provides some guidance on cold-weather masonry construction practices. Cold temperatures can slow the rate of curing of cement-based materials. In addition, these materials can be damaged if they freeze. The Masonry Standards Joint Committee and the Masonry Industry Council have both developed recommendations for cold-weather masonry construction that require special procedures any time the air temperature falls below 40 deg F. In each of these reference sources, the requirements vary depending on the temperature, becoming more stringent as the temperature drops. Although accelerating admixtures are often used to speed up setting of the mortar so that it can resist freezing temperatures sooner, no admixtures should be used unless they comply with the ASTM standard specification for admixtures for masonry mortars.