Concrete joint sealing and crack repair
Close the openings that let rain and snowmelt reach the soil under your concrete.
Joints are built into concrete on purpose, and gaps open up between slabs and along the house over time. Each one is a path for water. Around Sioux City, where loess silt erodes easily once it's wet, water moving through a joint can carry fine soil out from under a slab and leave a hollow. Sealing joints and cracks with a flexible sealant cuts that off.
Where sealing matters most
- The joint where a stoop, patio or driveway meets the house
- Control joints in driveways, especially sloped ones
- Cracks that opened after a slab moved
- Drill holes and joints after a leveling job
What it won't do
Sealant won't raise a slab that has already sunk, and it won't fix surface flaking from salt. It's upkeep that helps leveled and new concrete last.
How often should joints be resealed?
Flexible sealants break down from sun, traffic and the slabs moving through hot summers and cold winters. Check them every spring and reseal anywhere they've split or pulled away.
Is it a do-it-yourself job?
Narrow joints can be filled with self-leveling concrete sealant from a hardware store. Wider joints need foam backer rod first. A whole driveway, or joints after leveling, are often better left to a contractor.
Why seal after a lift?
Leveling fills today's void. If joints stay open, runoff can start carving a new one. Ask whether your leveling contractor includes sealing.
Pricing comes from the contractor after a site visit, once they've measured the drop and found what's under the slab. We don't quote prices, and the city's own sidewalk rates aren't a guide to what a private leveling job will cost.
Where we connect you with help
Common questions
When is the best time to seal concrete joints?
In dry, mild weather when the concrete is clean and dry, usually late spring through early fall.
Will sealing fix a slab that's already sunk?
No. A sunken slab needs leveling first. Sealing helps keep it from sinking again.
Related services
- Mudjacking and foam leveling
- Sidewalk repair and city notices
- Driveway and garage apron repair
- Steps, stoops and patios
More background: Sioux City concrete repair guide.
White paint on your sidewalk, or a slab that keeps dropping?
Call and a local concrete leveling contractor will look at it and quote the repair.