Concrete Contractors near you

Buried lines are marked before anyone digs. In Quebec, the Régie du bâtiment du Québec asks contractors to request a free locate from Info-Excavation at least 4 business days before work starts; in Ontario, a locate through Ontario One Call is free and legally required at least 5 business days ahead. Private lines, such as power to a garage or gas to a barbecue, are located separately. Then the work follows this order:

Outdoor concrete fails from the top down more often than it breaks. Water absorbed by the surface freezes, expands and pops off thin flakes, known as scaling, and de-icing salts make it worse by keeping the surface wet and adding freeze-thaw cycles. Flaking steps and pitted walkways are the usual result, especially where the surface was finished too wet or poorly cured.

The main defence is ordered at the plant. Air-entrained concrete holds countless tiny, evenly spread air bubbles, created with an admixture, that give freezing water room to expand without cracking the paste. For exterior flatwork and steps, ask the contractor to confirm that the mix is specified for freeze-thaw and salt exposure rather than general use, and keep de-icing salt off new concrete, using sand for traction instead.

Cold also affects the pour itself. Fresh concrete must not freeze before it has gained enough strength, so late-fall work calls for heated materials, insulated blankets or enclosures and close attention to the forecast, and concrete is never placed on frozen ground, snow or ice.

Concrete shrinks as it dries and moves with temperature, and because it's weak in tension, it cracks. Control joints decide where: grooves tooled into fresh concrete or saw-cut soon after it hardens create a weak line, so the crack forms neatly at the bottom of the groove instead of wandering across the slab. They need enough depth, good timing and a layout in roughly square panels, with extra joints at inside corners and around drains. Isolation joints, a flexible strip where a slab meets a foundation, steps or another slab, let each piece move on its own.

A hairline crack inside a control joint is the joint doing its job. Cracks that cross panels, widen each season or leave one side higher than the other point to a weak base, missing joints, roots or frost heave, and are worth showing to a contractor before they become a trip hazard.

Structural concrete, such as footings for an addition, deck or garage, a foundation wall or a garage slab, usually needs a building permit, and the municipality may ask for drawings and inspect footings before the pour. Replacing a walkway or patio at grade often doesn't, but zoning can still limit how much of a front yard is paved, how close a slab comes to lot lines and where runoff goes. Check before the forms go in, and settle who applies for the permit.

Widening a driveway or adding one where the curb is continuous involves the city, since the curb and sidewalk are public property. In Montreal, for example, a borough permit is required before a curb cut is created, removed or modified, and the city does the sidewalk work itself at the owner's expense. Other municipalities set their own rules, so that approval comes before the driveway is poured.

Surface damage can often be repaired. Light scaling or spalling can be patched or covered with a bonded resurfacing layer once loose material is removed, though overlays fail on slabs that still move or stay saturated. Cracks can be cleaned and sealed to keep water out, and a slab that has sunk in one piece can sometimes be raised by injecting grout or foam beneath it.

Replacement is the better choice when a slab is broken into many pieces, heaved and settled in different directions or crumbling through its depth, or when steps have pulled away from the house. Patching a slab whose base is failing only buys time. The cause, usually drainage or poor compaction, is corrected before new concrete goes in.