Hot Weather Masonry – Material Cooling
Masonry sand comprises approximately 75% of the mortar mix.
Sprinkling of masonry sand stockpiles can increase the evaporative cooling of the sand and prevent rapid absorption of the mixing water by hot, dry sand and subsequent early stiffening of the mortar. Cool water should be used to mix mortar and grout.
Ideally, the water should be stored in the shade in a lightcolored, open barrel to maximize cooling from surface evaporation. Water from long hoses exposed to the sun should not be used. When exposed to sunlight, long hoses act as water heaters. When practical, ice may be added to the mix water. Complete melting of the ice must take place before the water comes into contact with the other mortar or grout ingredients.
Equipment used to mix, transport, and store mortar and grout needs to be flushed thoroughly with water immediately before use. Mortar can absorb heat from metal mixers, wheelbarrows, and mortar pans, and lose water to the wood mortar boards.
Resource: Masonry Institute of St. Louis – www.masonrystl.org
Hot & Cold Weather Masonry-Publication of Masonry Industry Council