Minnesota Residential Roofer Practice Test

Masonry foundation walls need a mortar with high compressive strength and low permeability to handle loads, moisture, and soil conditions. Mortar types are defined by strength and composition, and for foundations the standard practice is to use the stronger end of the range. Type M and Type S deliver the required structural performance: Type M offers the highest strength, making it well-suited for footings and below-grade walls, while Type S provides strong performance with good bonding and durability in damp exterior conditions. Type N is a normal-strength, general-purpose mortar more common for above-grade, non-submerged walls, so it isn’t as suitable for foundations. The weaker mortars, Type O and Type K, are intended for non-load-bearing or special-purpose uses and wouldn’t meet the demands of foundation walls.