Homes built in the late 1930’s to the 1970’s were often built with concrete block foundations. These days, builders mostly use poured concrete for foundations. However, concrete block still has a place as a viable material for foundations. When a foundation is small, such as a home addition or crawl space, builders can save money by using concrete blocks instead of subcontracting for poured concrete, this way foundations can be quickly and economically built.
Concrete block foundations can show their problems in a number of ways; horizontal cracks in the mortar joints, horizontal shearing on the bottom of the walls, stair-step cracks in outside corners, tipping at the top of the wall, or even bulging.
Depending on the direction of the crack, you may be able to discern the problem.
Horizontal Cracks in Block Foundations
Horizontal cracks in concrete block or brick foundations mean that your foundation is being subjected to lateral pressure. This means that the ground around your house expands when it’s wet, and then contract when it dries. This type of foundation damage is usually fairly serious.
Vertical Crack In Block Foundations
If your foundation has vertical cracks, this can mean that your foundation is having "settling" problems. This is usually caused by unstable soil conditions, which may cause your foundation to rise or fall in certain areas. In most cases, damage to a foundation caused by settlement can also be visible in other areas of your home, such as in door and window frames.
Vertical Cracks In Poured Foundation
If your foundation has recently been poured, it's possible that the type of damage will be visible as small, vertical cracks that run at a slight angle. This type of damage is caused by the shrinkage that occurs in drying concrete during the curing process. Most of the time, this type of damage is fairly inexpensive to fix.