Concrete Crack & Floor Repair in Boulder, CO

Concrete crack and floor repair is the least glamorous part of a coating job and the part that decides whether the floor lasts. A coating copies whatever is underneath it. Leave a crack open and it shows through, and in a Front Range garage, de-icer meltwater finds it, freezes and pushes it wider. Leave a scaled patch by the door and the new coating has nothing solid to hold on to.

Slabs in Boulder and the surrounding towns take damage from two directions. From above, magnesium chloride brine and freeze-thaw cycles scale and pit the surface; research for state transportation departments has found concentrated magnesium chloride can chemically attack concrete. From below, swelling clay soils, which the Colorado Geological Survey calls the state's most significant geologic hazard, crack and lift garage and basement slabs.

The common problems we repair

• Scaling: the top layer flakes off in patches, usually from de-icer and freeze-thaw
• Pitting: small craters across the surface, often where brine has dried repeatedly
• Shrinkage and soil-movement cracks: hairline to wide cracks across the slab
• Worn control joints: the saw-cut lines that let concrete crack in a straight line, chipped at the edges
• Old patches: earlier repairs that have loosened or sit higher than the floor around them

Repair is not the same as structural work

The repairs we make are surface repairs: filling, patching and grinding the slab flat so it is sound and ready for a coating. A slab that is still heaving, or has one side of a crack sitting much higher than the other, may have an active soil or drainage problem underneath. That calls for a geotechnical engineer, a concrete contractor or a foundation specialist, and we will tell you if we see signs of it rather than covering it up.

Reading the cracks in your floor

A fine, straight crack along a control joint is normal. A web of fine surface cracks usually comes from how the slab cured. A crack that keeps widening, cracks that radiate from one corner, or doors and walls nearby that have started to stick or crack can point to soil movement. Telling those apart is the first thing we do at the estimate.

Repair on its own

Not every homeowner wants a coating right away. If you simply want a garage or basement floor that is sound and easy to sweep, we can repair cracks and scaling and grind the slab without coating it. Most people do coat afterward, because a bare repaired slab will start taking on de-icer and stains again.