It’s normal for buildings to have cracks in their walls. Most of the cracks that appear in walls are small and harmless. They are typically caused by factors such as settling, changes in temperature or changes in moisture, and are usually of no structural concern.
However, certain cracks can be worth worrying about. This post explains exactly when you should start worrying about cracks in walls.
Cracks with discolored brownish/yellowish edges
If cracks are discolored around the edges (usually a brownish or yellowish color), it could be a sign you have a leak. A leaky window or doors could be letting in rainwater. This could be softening up the plaster in your wall and causing it to crack.
While these cracks may not be a sign of major structural damage, you should still worry about the fact that there could be a leak. Such leaks could gradually lead to greater water damage and mold growth, so it’s worth locating this leak and patching it up as soon as you can. Check out this post at for more information on locating water leaks around your home.
Cracks that are jagged or diagonal
A crack that is vertical or horizontal is usually nothing to worry about. This typically means that the plaster is affected but the brickwork is fine.
A crack that looks jagged or travels diagonally up your wall in a stair-case motion is usually a little more alarming. This is a sign of a structural issue such as weak foundations and could be a sign that your home is on the verge of collapsing! While you can seal up this crack with caulk, it won’t solve the problem - you may be better off seeking foundation repair using a company such as Pinnacle Foundation Repair. At the very least, you should get the wall inspected by a professional.
Cracks that are over 1/8th of an inch wide
Most cracks are less than 1/8th of an inch wide. These ‘hairline’ cracks are a sign that your plaster is damaged, but are usually not a danger. This guide explains more about patching up these types of cracks.
A crack that is wider than 1/8th of an inch is usually something structural. Once cracks get larger than 1/4th of an inch wide you should really start getting worried - if you can fit a pencil in the crack, it’s not only a structural concern, but it’s large enough to allow small rodents in. If you can see sunlight poking through the crack, it means that the crack has penetrated the entire wall. Foundation issues could also be the cause of these cracks and you should get them inspected as soon as possible.
Cracks above windows and doors
The wall above a window or door is typically much weaker than the rest of the wall - particularly if it’s a load-bearing wall. If wide or jagged cracks start forming here, you should ask a professional to take a look immediately. The Washington Post goes into detail here about how to assess the damage and solutions to help.
This is similarly likely to be due to a structural issue such as foundation issues. In some cases, it may simply be a case of reinforcing the wall above the window or door. Whatever the case, it is definitely not the type of crack you should ignore.