What Is Concrete Joint and Crack Sealing?
Concrete joint and crack sealing fills and seals the control joints and cracks in flatwork so rainwater cannot run through them into the base beneath the slab. It is a preventive and protective repair: water entering open joints and cracks is what erodes the supporting soil and drives the settlement, sinking, and gaps that lead to bigger concrete problems. By keeping water out, sealing protects the base and extends the life of driveways, sidewalks, patios, and slabs. APS seals joints and cracks after correcting any existing settlement, so the slab is both level and protected against the water that would undermine it again.
How Concrete Joint and Crack Sealing Works
The joints and cracks are cleaned of old sealant, debris, and vegetation so the new sealant bonds. A flexible, weather-resistant joint sealant is applied to fill the opening and create a watertight seal that still allows the concrete to expand and contract. Because the joints and cracks are sealed, rainwater sheds off the surface instead of running underneath, which protects the base soil from the erosion that causes settlement. Where a slab has already settled, APS lifts it first, then seals, so the repair is complete.
“Sealing joints is the cheapest concrete work we do and it prevents the most expensive. Keep the water out and the slab keeps its support.”
How APS Installs Concrete Joint and Crack Sealing
- 1
Inspect Joints and Cracks
APS identifies the joints and cracks that are open or failing and checks whether any slab has already settled and needs lifting first.
- 2
Clean and Prepare
Old sealant, debris, and vegetation are removed from the joints and cracks so the new sealant bonds to clean concrete.
- 3
Apply the Sealant
A flexible, weather-resistant sealant is applied to fill and seal the openings while allowing normal concrete movement.
- 4
Tool and Finish
The sealant is tooled for a clean, watertight finish that sheds water off the surface.
- 5
Verify the Seal
APS confirms the joints and cracks are sealed and water is directed off the slab rather than under it.
What Concrete Joint and Crack Sealing Costs and What Is Covered
Cost Range
Cost depends on the area and surface condition. APS provides a free written estimate after the assessment.
Warranty
APS in-house workmanship warranty plus manufacturer warranties on materials, both fully transferable to future owners
Frequently Asked Questions
Why does sealing joints matter so much?
Open joints and cracks let rainwater run straight into the soil under your slab, where it erodes the support and causes settlement. Sealing keeps the water out, which is one of the cheapest ways to prevent sinking and cracking concrete.
Is joint and crack sealing a one-time fix?
Sealant is durable but is a maintenance item that is renewed over the years as it ages. Keeping joints sealed is ongoing protection for your concrete, and APS advises on timing.
Can you seal a crack in a slab that is still moving?
If the slab is settling, sealing alone will not hold, because the movement keeps reopening the crack. APS corrects the settlement by lifting and stabilizing the slab first, then seals so the repair lasts.
Will sealing stop my concrete from cracking?
Sealing prevents the water-driven base erosion that causes much of the cracking and settlement, and it keeps existing cracks from letting water in. It is preventive protection rather than a guarantee against all cracking, and it meaningfully extends slab life.