Why Is My Brick Foundation Cracking in Winter?
Last updated October 25, 2026
The short answer
How Freeze-Thaw Cycles Damage Brick
Brick is porous. During winter, melting snow and rain can soak into the surface and the mortar between bricks. When temperatures drop below freezing, that trapped water expands by about 9 percent. The expansion pushes outward against the brick and mortar, creating stress that leads to cracking.
Repeated cycles of freezing and thawing make the damage worse. Each cycle adds more stress, and small hairline cracks can grow into larger ones over time. If your foundation faces north or is shaded, it may stay frozen longer, which can increase the number of freeze-thaw cycles it experiences.
The Role of Water and Drainage
Water is the main driver of winter cracking. If your gutters are clogged or the ground slopes toward your foundation, water pools near the base. That water has a chance to seep into the brick and mortar before it freezes. Improving drainage can reduce the amount of moisture that reaches your foundation.
Check the grading around your home. The soil should slope away from the foundation so water runs off instead of collecting. Downspout extensions can carry roof water farther from the house. Keeping the area clear of snow and ice can also help, but avoid using deicing salts near brick, as they can cause spalling.
- Clean gutters and downspouts before winter
- Extend downspouts at least a few feet from the foundation
- Ensure the ground slopes away from the house
- Clear snow away from the foundation base
- Avoid deicing salts near brick, as they can damage the surface
Ground Movement and Frost Heave
Frost heave happens when water in the soil freezes and expands, lifting the ground. That movement can push against your foundation and cause cracks in the brick. The effect is more likely in soils that hold a lot of water, like clay. If your foundation sits on such soil, winter heaving can be a recurring issue.
The damage may not be uniform. One corner of your foundation might lift more than another, creating uneven stress. This can show up as vertical or stair-step cracks in the brick and mortar. If you notice new cracks appearing each winter, ground movement is a likely culprit.
When to Call a Professional
Not every crack is an emergency, but some signs point to a bigger problem. Large gaps, cracks that keep growing, or bricks that are loose or shifting should be checked. Also, if you see water seeping through the foundation into your basement or crawl space, that needs attention.
A local water damage pro can inspect the foundation and identify the cause of the cracking. They can also check for hidden moisture issues that might be making the problem worse. Look for pros who understand the local soil and building conditions.
Preventing Future Winter Cracks
Prevention focuses on keeping water away from the foundation. Good drainage, proper grading, and functional gutters are your first line of defense. You can also apply a water-repellent sealant to the brick, but that only works if the brick is in good condition and the sealant is applied correctly.
Inside your home, control humidity in the basement or crawl space. A dehumidifier can help reduce moisture that might seep through the foundation. Insulating your foundation and keeping the interior warm can reduce the number of freeze-thaw cycles the brick experiences.
- Inspect and clean gutters each fall
- Check for and fix any cracks in the foundation before winter
- Seal the brick with a breathable water repellent if needed
- Use a dehumidifier in the basement or crawl space
- Keep the interior temperature consistent to reduce freeze-thaw stress
Talk to someone now
Phones are answered 24/7 for South Jordan and nearby communities.
Call Now (801) 845-3042Frequently asked questions
Are small hairline cracks in my brick foundation a problem?
Small hairline cracks are common and may not be urgent, but they can let water in. Over winter, that water can freeze and make the crack larger. Watch them and seal them if they grow or if you see water inside.
Can I fix the cracks myself?
You can fill small cracks with a masonry caulk or mortar repair product, but the fix may not last if the underlying cause is water or ground movement. For larger or recurring cracks, it's sensible to have a pro assess the situation.
Will my insurance cover foundation crack repairs?
Policies vary, and your insurer decides what is covered. Some policies exclude damage from freezing or ground movement. Check your policy and ask your insurance company directly about your specific situation.