Concrete Floor Resurfacing Or Slab Replacement
The threshold most engineers work to is roughly a quarter to a third of the floor area. Below that, with the subgrade intact and the slab thick enough for the loads now running on it, concrete floor resurfacing is the right call. Above it, or where the ground underneath is failing and the joints are pumping, replacement is the honest answer and we will say so.
The other half of the decision is time. Full depth replacement puts a section of floor out of service for three to seven days and the racking has to come out. Partial depth repair returns in one to three days. Grinding out a trip hazard returns immediately. In a building that is still shipping, the downtime usually dominates the material cost by a wide margin, which is why concrete floor resurfacing is frequently the cheaper option even when the square foot rate is not.
Where racking loads have been increased since the building was put up, or the truck fleet has got heavier, the original slab design may simply not be adequate any more. That is worth knowing before money goes into a surface.
What Concrete Floor Resurfacing Actually Involves
Concrete floor resurfacing starts with removal. Old coatings, curing compound, sealer, laitance and surface contamination come off mechanically. Shot blasting handles the open field quickly and diamond grinding handles the edges, the columns and the corners.
Spalls are saw cut to a square boundary, the unsound concrete is taken out, and the void is filled with a structural repair material rather than feathered over. Feathered edges break away again within months.
Cracks are routed out to a clean section and filled as part of the concrete floor resurfacing. Whether they get an epoxy or a flexible material depends on whether the crack is dormant or still moving, and that is a judgement made on site rather than from a photograph.
Joints get treated as their own scope, because they are the largest hidden number in most industrial floors. Our concrete joint repair page sets out what that involves.
Finally the concrete floor resurfacing is re-profiled to whatever the specified system needs. The profile has to match the thickness of what is going over it.
Halifax Slabs Need Concrete Floor Resurfacing For Local Reasons
Much of the ground under this city is the slate and greywacke of the Halifax Formation, and parts of it carry enough pyrite and pyrrhotite that the municipality regulates the material as sulphide bearing. When that rock is exposed to air and water it generates acid, and acidic groundwater is corrosive to concrete foundations.
Add a winter that crosses the freezing point most days rather than staying below it, road salt arriving on every vehicle that comes through the door, and humidity that sits between three quarters and four fifths saturation all year, and Halifax slabs get a chemical and thermal load that a dry inland building simply does not see.
None of that means a floor cannot be saved by concrete floor resurfacing. It means the diagnosis has to come before the quote, which is why we test the slab rather than pricing off a drawing.
