Concrete Repair near you

Flatwork repair deals with slabs on the ground, outdoors or in a garage. A crack in a basement wall, a crack letting water or soil into the basement, a slab pushing against the foundation, or new cracks appearing along with sticking doors and windows upstairs belong to a different job. The foundation cracks page explains how those are assessed and sealed, and when a structural engineer should see them first.

Outdoor slabs can also be the cause rather than the symptom. A walkway or patio that has settled toward the house sends rain and meltwater against the foundation, and a gap where a slab meets the wall lets water run straight down beside it. Lifting the slab to restore the slope, or sealing that joint with a flexible sealant, often protects the foundation as much as the slab.

Crack repair depends on whether the crack still moves. Outdoor slab cracks usually do, with temperature and frost, so they're cleaned out, sometimes widened slightly with a grinder to give the sealant a clean, even channel, fitted with a foam backer rod if deep, and filled with a flexible sealant made for concrete. Rigid fillers such as epoxy lock the two sides together, but if the slab keeps moving it cracks again beside the repair, so they're kept for dormant cracks and specific structural work.

A spall or broken edge is repaired by removing everything loose down to sound concrete, cutting the edges of the patch square so it isn't feathered thin, and cleaning the area. Exposed steel is cleaned of rust or treated, a bonding agent is applied if the product calls for one, and a repair mortar rated for outdoor freeze-thaw exposure is packed in and finished to match the surrounding texture. The patch then cures as its maker directs, protected from sun, wind and frost. Expect it to stay visible: a patch almost never matches weathered concrete exactly.

Resurfacing puts a thin, bonded layer of polymer-modified cement over a scaled or worn slab, giving a fresh, even surface without a tear-out. It only works on concrete that is sound underneath: reasonably flat, not heaving and not saturated. Preparation decides whether it lasts. Weak surface material is removed by grinding or blasting until the slab is rough and clean, cracks are dealt with first, and existing joints are carried through the new layer so they don't come back as random cracks.

That grinding, along with saw-cutting patch edges and widening cracks, raises fine dust containing crystalline silica. The Canadian Centre for Occupational Health and Safety (CCOHS) says breathing it in can damage the lungs and lists crystalline silica as a known cause of lung cancer; it advises against dry sweeping or compressed air for cleanup and recommends water to keep dust down or an approved HEPA vacuum. Expect a contractor to use grinders with dust extraction or wet methods and suitable respirators, and keep children, pets and open windows away from the work.

Steps show damage first at the nosings and corners, where edges are exposed on two sides and take the scrape of shovels. Broken edges can be rebuilt with repair mortar held in temporary forms, and a scaled tread can be resurfaced, as long as the core of the step is solid. Railing posts set into the concrete are a common weak spot: water collects around a rusting post, freezes and splits the concrete, so the repair should include re-anchoring the railing and sealing around it.

Walkways usually need crack sealing, lifting of settled panels, or grinding down a small lip where one panel sits higher than the next. When steps have pulled away from the house, tipped forward, crumbled through their depth or sit on a failing base, patching isn't worth it; the concrete contractors page covers replacement. Any step or walk with a lip, a loose edge or a wobbly railing is a fall risk in winter and should be fixed before the first snow.