We’ve all heard nightmare stories of how foundation cracks or cracks in walls could signify major problems. However, not every crack is a reason for alarm. Let us explain the differences so you’ll know what they mean and when you should be concerned.
Vertical Cracks in Basement Walls
As the concrete walls or blocks cure, they begin to shrink and may result in small vertical cracks. These cracks may be barely visible while others can be a bit larger. While most vertical cracks are not usually a sign of distress, water can penetrate through if the waterproofing material on the wall’s exterior lacks the suppleness necessary to protect the crack. If the cracks are less than 1/8” wide, consider filling them with a waterproof sealant to prevent moisture from entering the basement. However, if the vertical cracks are 1/8” wide or bigger, you should have it inspected.
Horizontal Cracks in Basement Walls
Horizontal cracks along the intermediate height of basement walls sometimes occur from the pressure of exterior dirt. As long as that area of the wall is not protruding inward from stress, most likely the structural integrity isn’t compromised. However, it’s a good idea to monitor the crack and the wall for any changes.
Diagonal Cracks in Basement Walls
Diagonal cracks frequently exist in concrete basement walls, typically due to one of three reasons.
The most common type will move diagonally from the top edge of a concrete basement wall down towards a corner. When there is also an inward tilt present at the highest point of the crack, the issue is typically caused by missing anchor bolts in the framing that attaches the basement wall to the floor above, which results in the wall being shoved in from the earth.
Another type of diagonal crack that indicates the foundation is settling will occur in random places on concrete basement walls. This is when the top portion of the fracture will be wider than the lower portion.
Finally, cracks that run diagonally from the corners of window frames or door frames is generally the same scenario as vertical cracks and caused by the concrete shrinking.
Basement walls made of concrete blocks often develop stair step cracks, which are usually caused by same problems as the diagonal cracks on concrete walls
Foundation Cracks in Crawlspace or Garage
The foundation walls in both crawlspace areas and garages are shallower than basement foundations, making them more susceptible to temperature and moisture changes of the surrounding soil as it dries out, freezes or soaks up water. These climate fluctuations will cause cracks in foundation walls and drywall finishes. Sometimes, additional support is essential.
Foundation Cracks on Exterior Corners
Triangular cracks tend to form on foundation corners as the concrete cures and contracts. On houses that have brick veneer installed, the veneer material will expand, while the concrete shrinks, causing it to fall off. This is more than likely only a cosmetic issue and is normal.
Cracks in Concrete Slabs
Just as concrete walls shrink as they cure, so do concrete floor slabs in basements and garages. During the curing process, the concrete begins to harden and will often crack, especially near the control joints, which are the weakest points. Usually this is only an aesthetic issue, however, these slabs are supported by the underlying ground, and cracks more than one-quarter inch wide could indicate the ground beneath the slab is settling or failing.
Essentially, cracks in concrete occur from lots of variables, so if you’re concerned, consult a professional home inspector.
The Author Adam Clark is the owner and operator of Shield Guard Home Inspections. Adam Clark is a local Home Inspector located in Albany NY that has performed over 6000 Inspections
Phone: (518) 720-7152