Houston Foundation Cracks: Which Are Normal and Which Are Warning Signs
Key Takeaway
Houston's clay soil shrinks and swells, so foundations move all the time. Straight cracks in sheetrock and cracks in the mortar are usually just settlement. Cracks that go through the brick or zigzag across a door frame are warning signs. And keep at least 3 to 4 inches of your foundation showing above the mulch so termites can't get in through the weep holes.
Owning a home in Houston means living on soil that expands and contracts like a sponge. Foundation movement isn't a maybe here, it's a given. What matters is knowing the difference between a house doing what houses do and a house telling you something is wrong.
Why do Houston foundations move?
Our soil here is clay. Locals call it gumbo, and I don't know where that name came from, because you certainly can't eat it. Clay shrinks and swells. Think of a sponge: with no water in it, it gets real small, and then it gets big again. That means your foundation is moving all the time, so some cracking is just part of owning a home here.
Which cracks are normal, and which are warning signs?
A lot of what homeowners notice is simply settlement, and the age of the house plays a part too. Here's how I sort it out:
- A crack in the sheetrock that runs in a straight line: no problem.
- Cracks in the mortar between the bricks: usually not a problem.
- A crack that goes through the brick itself: that's a problem.
- A crack that zigzags across a door frame: that's a problem.
If you're seeing cracks like the last two, don't ignore them.
How can too much mulch lead to termites?
Here's one most homeowners never see coming. Gardeners love to put mulch in the flower beds. It's a good return for them because they buy it in bulk and put it down. The problem is that over the years, it builds up too much.
Termites are sometimes already in that mulch. If the mulch covers your foundation, they can go right through your weep holes and into your house, and now you've got termites. Always keep at least 3 to 4 inches of your foundation showing above the soil, and 4 inches is better.
What about older Houston homes?
In a lot of older homes in Houston, the soil was built right up to the foundation. If that describes your house, it might not be a bad idea to look into termite barriers.
Know your home. It saves you money.
Knowing what's normal for a Houston house, and what isn't, helps you protect your biggest asset. If you have questions about a home you own or one you're thinking about buying, contact HomeCoach. This is C.W. Ross, certified real estate planner and multigenerational HomeCoach.
Frequently Asked Questions
Why do foundations move so much in Houston?
Houston sits on clay soil, often called gumbo, that shrinks and swells like a sponge as it dries out and takes on water. That keeps foundations moving all the time.
Are cracks in the mortar between bricks a problem?
Usually not. Cracks in the mortar, and straight-line cracks in the sheetrock, are typically just settlement.
Which foundation cracks are warning signs?
Cracks that go through the brick itself, or that zigzag across a door frame, are a problem and shouldn't be ignored.
How much of my foundation should be showing above the mulch?
Keep at least 3 to 4 inches of foundation showing above the soil and mulch, and 4 inches is better. Mulch built up against the foundation can let termites get through the weep holes into your house.
What should owners of older Houston homes watch for?
Many older Houston homes have soil built right up to the foundation. In those homes, termite barriers might be worth considering.