The short answer
What Causes Cracks After a Flood
When floodwater soaks the ground next to your home, the soil expands and pushes against the foundation. This added pressure, called hydrostatic pressure, can cause the concrete to crack, especially if there are weak spots or existing hairline fractures.
As the water recedes and the soil dries, it can shrink and settle unevenly. This movement can create new cracks or widen existing ones. The type of soil around your home plays a big role, with clay soils being more prone to swelling and shrinking.
- Hairline cracks in the concrete surface
- Vertical or diagonal cracks that extend through the wall
- Gaps between the foundation and the soil
- Widening of existing cracks
- Cracks that appear after the soil dries
Is It a Serious Structural Problem
Not all cracks signal a major issue. Hairline cracks, often less than a quarter-inch wide, are usually cosmetic and can be sealed with a flexible masonry filler. They may not require professional help unless they leak water or grow over time.
Wider cracks, especially those that are vertical or step-like, can indicate structural movement. If you notice doors or windows sticking, floors sloping, or cracks that continue to expand, it's worth having a professional inspect the foundation. A structural engineer can provide a definitive assessment.
- Check if the crack is wider than a quarter-inch
- Look for signs of shifting, like sticking doors or windows
- Monitor the crack over a few weeks for growth
- If water seeps through the crack, address it quickly
- Seek professional advice if you have any doubts
How to Manage the Situation Right Now
First, ensure the area around the foundation is draining properly. Remove any debris that might block gutters or downspouts, and grade the soil away from the house so water doesn't pool next to the walls. This helps reduce further pressure on the foundation.
Keep an eye on the cracks. Take photos with a ruler next to them to track any changes. If cracks appear to widen or new ones form, that's a sign the soil is still moving. You might want to contact a local water damage pro for a thorough inspection.
When to Call the Pros
If you see cracks wider than a quarter-inch, or if they are accompanied by other signs of foundation movement, it's time to call in local water damage pros. They can assess the situation and recommend the right course of action, which might include foundation stabilization.
Also, if you notice water seeping through the cracks during heavy rain, that's a clear sign you need professional help. Water intrusion can lead to more damage, including mold growth, so addressing it early is important.
Preventing Future Cracks
After the flood, make sure the soil around your foundation is properly compacted and sloped. In a semi-arid climate with cold winters and hot dry summers, the soil can undergo significant changes, so maintaining good drainage is key. Consider extending downspouts away from the house.
If you live in Caldwell, keep the ground near your foundation as dry as possible during normal times. This can help reduce the risk of cracking in future flood events. Regular inspection of your gutters and grading can catch problems early.
Talk to someone now
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (208) 729-2441Frequently asked questions
Can I fix a foundation crack myself?
Small hairline cracks can be sealed with a flexible masonry caulk. For larger cracks, especially those that are structural, it's a sensible choice to have a professional assess the situation. DIY fixes on serious cracks can fail and lead to bigger problems down the road.
How long does it take for cracks to appear after a flood?
Cracks can appear as the soil dries and shrinks, which may take several weeks or even months. The timing depends on soil type and weather conditions. Monitor your foundation regularly after a flood to catch any changes early.
Will my insurance cover foundation crack repairs?
Policies vary, and your insurer decides what is covered. Flood damage is often excluded from standard homeowners policies, but you may have separate flood insurance. Check your policy documents and discuss with your insurance agent to understand your coverage.