Repair & Resurfacing

Most of Arlington, Mansfield, Grand Prairie and Fort Worth sits on expansive clay: soft and high after spring rain, hard and low by late August. Edges lift where water collects, centers settle where a tree pulls moisture out, and the slab cracks where the two movements meet. The concrete did not get weaker — the subgrade changed shape, and concrete has almost no ability to bend. The longer version is on why concrete cracks.

The practical point for repair: if we do not deal with the water, the repair fails the same way the original did. Downspouts dumping next to the slab, a flower bed that holds water against the edge, a gutter that drains across the drive. Those get fixed first, or the job is not worth doing.

Hairline cracks that stay flat are cosmetic; concrete shrinks as it cures, and that is what control joints are for. A crack wide enough to drop a coin in, or one where one side sits higher than the other, means the subgrade moved. That offset is also the trip hazard: the ADA Standards allow up to 1/4 inch vertical, require a bevel from 1/4 to 1/2 inch, and treat anything past that as a step.

Spalling — the top surface flaking off and exposing the aggregate — is a surface problem on a sound slab, usually from a weak finished layer, too much water in the mix, or deicer. A slab that has settled, heaved, or pumps water at the joints when you drive on it has a void underneath, and that is a subgrade problem.

Patching fits spalled spots, chipped edges and small holes on a slab that is otherwise sound and stable: we cut the edges square, remove everything loose, and fill with a polymer-modified repair mortar. Be honest about the look, because a patch never matches perfectly. Resurfacing — a thin overlay, 1/8 to 3/8 inch — is for a slab that is ugly all over but no longer moving; it cannot stop a live crack, which telegraphs through within a season.

Lifting, by mudjacking or polyurethane foam, brings a settled panel back to grade, but only one that went down in one piece: a heaved slab cannot be lifted down. Cutting out and replacing a panel is the answer when one section is broken or badly offset. We cut at the existing joints, rebuild and compact the base, dowel the new panel into its neighbors and match thickness and finish. Replacing the bad panel instead of the whole driveway or walk is usually the best value on the list.

Some slabs are past saving, and we would rather say so. If more than a third of the panels are cracked or offset, the subgrade has failed across the whole thing. A slab under about 3.5 inches, one with no steel in it, one shedding sand when you sweep it, or one already lifted once and settled again will keep breaking no matter how good the patch is.

Full replacement of 4-inch broom-finish flatwork runs about $8 to $14 per square foot installed, plus $2.50 to $4.50 to break out and haul the old slab; the driveway, patio and slab cost pages run that math on real sizes. If the concrete is coming out anyway and you have wanted a carport or a covered patio, this is the moment to plan both: we pour the pad, CJM Metals builds the steel on it.

Prep decides the result. Every repair edge gets saw-cut square so the new material bonds to a clean face instead of a feathered edge that chips out in a year, loose material comes out down to sound concrete, and where a panel is replaced the base gets re-compacted or rebuilt with crushed stone that drains. New panels are doweled into the old concrete so the pieces move as one, and the new joints line up with the existing ones.

Then it cures. Repair mortars and new panels need their full cure time before they carry a car, and cutting that short is the most common way a good repair fails. Public sidewalk and the driveway apron at the curb are City right-of-way, so we confirm that with the City of Arlington (One Start Development Center, 817-459-6502) before we cut, and this page covers what usually applies.