Mortar is the mixture of cement or lime, sand, and water that bonds bricks or stones together and fills the joints between them, distributing load and sealing the wall against weather.
Mortar isn't glue. It's a bedding material that lets each brick or stone settle into place and spreads the load evenly across the wall, so a high spot or slight dip in one unit doesn't concentrate stress on the units around it. It's mixed from cement or lime, sand, and water, and the ratio of those ingredients determines strength and flexibility. Masons classify mortar into types, N, S, M, and O, chosen by what the wall actually needs to do structurally.
Getting the mortar type right matters more here than in milder climates. Southwest Virginia's foothills go through hard freeze-thaw cycles all winter, and mortar is supposed to be the sacrificial part of a wall, softer than the brick or stone so it wears and cracks first instead of the masonry unit itself. Use a mortar that's too hard or the wrong type for the application, and it holds moisture against the brick or lets stress crack the brick face instead.
More masonry vocabulary from the glossary.
The services where this term comes up.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
