Cracks in your foundation are never a fun discovery, and if you haven't had the chance to contact a professional yet, you may be wondering just what you're in for. Here are three types of foundation cracks and some tips on how to tell if they're likely to represent an urgent threat.
1. Vertical Cracks
Vertical cracks are the least likely to be an urgent threat, and nearly-vertical cracks, or ones that are only slightly diagonal, also count as vertical. In fact, these cracks are basically everywhere. These cracks often form when a new foundation is settling, and they basically need to be sealed up and waterproofed, but usually won’t cause you too much stress.
The exception is when you have an unusual vertical crack, such as:
- A crack that keeps getting wider and wider over time
- A crack that's noticeably wider at the bottom
- A crack that shows displacement, for example, one side of the crack is pushed in slightly or one side is either raised or lowered
Any cracks that show unusual behavior like this, especially if they're new or if you observe change, should be diagnosed professionally even though vertical cracks are generally considered low-risk foundational cracks.
2. Horizontal Cracks
These cracks can occur from a number of causes. Some horizontal cracks are very serious, while others are not. If it's an old, unchanged, hairline crack and both sides are flush, there may be nothing to worry about.
Problematic horizontal cracks tend to be those that keep changing whether widening, elongating, moving etc., or horizontal cracks that have uneven sides where it looks like part of the wall has been pushed in slightly.
If you know you have a clay soil that expands a lot, poor drainage near the foundation or some other problem that could affect the foundation, you should be suspicious of any horizontal cracks.
If you're not sure whether your crack is a problematic or more benign one, it's better to be safe than sorry — get a professional opinion. It's easy to mistake one crack for the other if you don't have a lot of experience.
3. Stairstep or Diagonal Cracks
Cracks that stretch diagonally are more likely to be problematic. A stairstep, or zigzag, is the type of crack that forms when your foundation wall is made of blocks, such as cinderblocks, whereas the same crack would likely form a diagonal line in a one-piece wall.
These cracks signal a problem, and if this problem is not dealt with it can cause serious foundation collapse.
While you shouldn't give up on your foundation just because this type of crack occurs, you should also never ignore it. Even a hairline crack that has a diagonal or stairstep nature should be taken as a sign that you need to work on your waterproofing and drainage efforts right away.
The wideness of this type of crack indicates how extreme of a problem it is. If it's quite wide it could mean that one section of the wall is continually sinking. If the sides of the crack are not flush, this could mean that the entire section is in danger of collapsing, possibly from freeze-thaw pressure or hydrostatic pressure. If you have a diagonal crack, it's likely that a portion of the wall will need replacing.
As you can see, there are a lot of factors that determine the seriousness of a foundational crack. These guidelines can help you estimate the urgency of crack repair, but they're no substitute for the repair itself. If you find a new or changed crack in your basement, get a professional opinion and remediation in order to make sure your crack is not going to be a threat to your home.
For more information on what we can do to help your foundation, contact Bayshore Construction, Waterproofing & Foundation using our easy online contact form at any time of day or night!