Concrete joint sealing and crack repair
Keep meltwater from getting under your concrete, which is what starts most settling to begin with.
Every slab has openings: the control joints cut into it, the seams between slabs, and the gap along the house. In Grand Forks, where about four feet of snow falls in an average winter and melts on flat ground, those openings let water reach the soil under the concrete. It freezes, thaws, softens the clay and carries fine soil away. Sealing joints and cracks with a flexible sealant slows that down.
Where does sealing help most?
- The joint where a stoop, patio or driveway meets the house
- Control joints in driveways and garage aprons
- Cracks that opened after a slab moved
- Drill holes and joints after a mudjacking or foam job
What sealing won't do
Sealant won't lift a slab that has already dropped, and it won't stop surface flaking from salt. It's upkeep that helps leveling, and new concrete, last longer.
How often should joints be resealed?
Flexible sealants wear out from sun, traffic and movement. Walk your concrete each spring after the thaw and reseal anywhere the sealant has split or pulled loose from the edges.
Why it's worth doing after a lift
A lift fills the void that's there today. If the joints stay open, the next spring's melt can start carving a new one. Many contractors offer sealing as part of a leveling job; ask whether yours does.
Can I seal joints myself?
Small, narrow joints can be filled with a self-leveling concrete sealant from a hardware store. Wide joints need a foam backer rod first so the sealant isn't too deep. A whole driveway's worth of joints, or joints after a leveling job, are often worth handing to a contractor.
We don't quote prices. The contractor sets the price after measuring the slab, finding the void and working out why it dropped, so treat any figure you hear before a site visit as a rough guess.
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. In Grand Forks that's usually late spring through early fall.
Will sealing fix a slab that's already sunk?
No. Sealing keeps water out. A slab that has already dropped needs mudjacking or foam leveling first.
Related services
- Mudjacking and foam leveling
- Sidewalk repair and city repair lists
- Driveway and garage apron repair
- Steps, stoops and patios
More background: Grand Forks concrete repair guide.
Slab dropped after the thaw, or a sidewalk on the city's repair list?
Call and a local mudjacking contractor will come look at it and quote the repair.