Sikaflex Self-Leveling / Crack Flex Sealant (10.1 oz) Review (2026)
By Nate Sawyer, Editor · Updated July 2026
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- Concrete cracks
- Driveway cracks
- Horizontal joints
A single-component self-leveling polyurethane for horizontal concrete cracks in driveways, patios, and garage slabs up to about 1.5 inches wide. It flows in and self-levels for a flush finish with no tooling, stays flexible with the slab, and bonds gray without primer. Limits: it only works on horizontal surfaces, and full cure takes 3 to 7 days.
Pros
- Self-levels into the crack for a smooth flush finish with no tooling required
- Cured polyurethane stays flexible and moves with the slab, resisting re-cracking better than rigid fillers
- Bonds without a primer to concrete and cures gray, blending into most driveways and slabs
Cons
- Self-leveling only works on horizontal surfaces; vertical or wall cracks need a non-sag product
- Deep or wide cracks need backer rod or sand first, or the tube empties fast
- Full cure takes several days, so keep traffic off the repair longer than a fast-set filler
Specifications
| Type | Single-component self-leveling polyurethane |
|---|---|
| Expansion | N/A (self-leveling, flows into crack) |
| Cure | Tack-free in a few hours, full cure in ~3-7 days |
| Paintable | Yes, sandable and paintable |
| Use | Horizontal concrete cracks up to ~1-1.5 in wide |
Frequently Asked Questions
- Why choose a self-leveling crack sealant?
- Because it does the finishing for you — it flows into the crack and levels flush with no tooling, which is hard to achieve by hand on a long driveway crack. Cured polyurethane also stays flexible and moves with the slab, resisting re-cracking better than rigid fillers.
- Can you use Sikaflex self-leveling on a wall crack?
- No. Self-leveling only works on horizontal surfaces; a vertical or wall crack needs a non-sag product or it simply runs out of the joint.
- How long must traffic stay off a Sikaflex self-leveling repair?
- Tack-free in a few hours but full cure takes about 3-7 days, so keep traffic off longer than you would with a fast-set filler. Deep or wide cracks also need backer rod or sand first or the tube empties fast.