Cracks in the walls of your home can indicate foundation issues. Some small cracks aren't anything to be concerned about, but others can indicate major foundation problems and worse — water damage that is already occurring. Knowing how to spot the dangerous cracks is a skill every homeowner needs to acquire.

Diagonal Cracks

Most walls develop cracks in one of two ways. Straight, horizontal or vertical cracks are typically nothing to be concerned about because they are usually the result of poor drywall taping, so fresh plaster will fix them right up. The type of cracks to be concerned about are diagonal cracks. It is especially alarming if the crack widens over time. A diagonal crack forms as a result of the foundation settling unevenly, and it can indicate that there are cracks forming in the foundation as well. Stresses on the framing of the house from the uneven settling results in the formation of these diagonal stress fractures in the walls.

Discolored Cracks

Discoloration around a wall crack is cause for immediate concern. Typically, the discoloration will take on a darker hue than the wall, or it may appear brown or yellow. In some cases the discoloration may be black or green as a result of mold and mildew growth. Discolored cracks usually occur around the floor when foundation damage is the culprit, but they can also appear near window or door frames. If the crack is a result of uneven foundation settling and the discoloration appears mid wall, check the siding of your home. Sometimes gaps can form as a result of the settling, which then lets moisture into the walls. The result is damp wall board and discoloration.

Window Frame Cracks

Cracks around window and door frames are sometimes a result of foundation damage. As the foundation settles, these cracks will form. Eventually the window or door frame will come out of square, which means it will stick when you try to open it or become difficult to close when you want it shut. These types of cracks don't always indicate foundation damage, though. In some cases they can just be a result of normal house settling and only need to be patched. For this reason, it is a good idea to have any window or door frame cracks assessed by a professional.

Contact a foundation repair service if you have any wall cracks. They can help you determine if your foundation needs to be inspected for possible damage.