When the ambient temperature around an in-progress masonry project falls below 40ºF, special procedures need to be implemented to ensure the masonry sets properly. With the winters we experience in the Milwaukee, Racine, and Kenosha areas, it is vital to keep them in mind.
Masonry in Cold Weather
Do not mix large amounts of mortar at a time, and keep any mixed mortar on a heated surface. This surface should not be too hot, otherwise the heat will prematurely dry the mortar.
Use an accelerator to speed up mortar and cement set time. Note: accelerators can change mortar color.
Cover any recently completed masonry work with tarps and keep building materials covered AND on top of planks.
Cover walls with plastic if the temperature is above freezing (32ºF). This will prevent water from getting into the setting masonry.
Install windbreakers if the wind around your masonry project is above (or is projected to go above) 15 mph.
Use a heated enclosure if the temperature goes below 20ºF.
Never lay masonry materials on surfaces with visible moisture -- including ice, snow, or water.