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Seal foundation cracks
Trigger
Hairline cracks noticed / before wet season
Who does it
DIY or Pro
Est. time
1-2 hrs
Est. cost
$20-100 (DIY kit)
Difficulty
●●○○○
Step by step
Clean the crack of debris and loose material with a wire brush.
For hairline cracks, inject masonry crack sealant/epoxy along the length.
For cracks wider than 1/4 inch or that are growing, have a foundation specialist assess it.
Grade soil away from the foundation to reduce future water pressure on the crack.
Monitor the crack over a season to confirm the repair is holding.
Questions to ask your pro
- How do you determine whether a crack is cosmetic versus structurally significant?
- What repair method do you use—epoxy injection, polyurethane foam, or hydraulic cement—and why for this crack?
- Will you mark the crack to monitor whether it is still actively growing before sealing?
- Do you address the underlying drainage or hydrostatic pressure cause, or only seal the symptom?
- Is interior drainage or exterior waterproofing also recommended in my situation?
- Do you offer a warranty on the repair, and for how long?
- Should I have a structural engineer assess this before or after repair?
Video guide
Search: 'how to seal foundation cracks DIY'
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