The snowbanks are gone off Hurontario and the county roads have stopped being white. This is the two weeks of the year when a garage floor tells you the truth about the winter it just had.
Get the car out, sweep it, and look at the concrete in daylight with the door open.
What you are looking for
A fine grey dust that keeps coming back. You sweep, and two days later it is there again. That is the surface of the slab breaking down and shedding. It is the earliest stage and the cheapest one to deal with.
Small round pits, a few millimetres across. Often clustered where the tires sit and just inside the door, because that is where brine drips off and pools.
Flaking in thin plates. Sheets of surface lifting away, sometimes the size of a coin, sometimes a hand. This is spalling proper.
A darker, damp-looking patch that has not dried out. Different problem — that is water from below, not salt from above, and it is worth knowing about before you plan any coating.
White powdery bloom. Efflorescence: mineral salts left behind by water moving up through the slab and evaporating. Again, a moisture signal rather than a salt one.
Why it happens here specifically
Every winter your car makes the trip home carrying brine off Highway 26 and the concession roads. It melts off in the garage and pools under the vehicle, and unlike the driveway, the garage floor never gets rain to rinse it.
Concrete is porous, so the chloride soaks in. Where it reaches the reinforcing steel it corrodes it, and rust takes up more volume than the steel it replaced — so it pushes the concrete above it off from the inside. Separately, salt increases the number of freeze-thaw cycles the surface goes through, and each one takes a little more.
That is why garage slabs in this region degrade faster than driveways of the same age, and much faster than the same slab would in a city that salts less.
The screwdriver test
The one useful thing you can do yourself. Take a screwdriver to the worst-looking area and drag it hard across the surface.
- It leaves a scratch line. Normal. The slab is sound and this is a coating conversation.
- It digs out loose material, and keeps digging. The surface has lost its section. You are into repair before coating — a polymer-modified overlay to re-establish a flat, sound surface, then a coating on top.
- You reach something that looks like rusted steel. Stop. That is deep spalling to the rebar and it needs cutting out and patching properly, and the honest answer on some slabs at that stage is replacement.
Why April, and not August
Two reasons to look now rather than later.
The damage is at its most visible. By July the dust has been swept a dozen times and the pitting has stopped being new, and it stops registering. In April it is obvious.
And this is the shoulder window. Late April into early May is one of only two stretches in the year when this region’s floor work is realistically bookable, and it is the same fortnight every property manager on the escarpment is trying to book for their chalet garages. The other window is late October into November, by which point you have lost the summer and you are coating a floor that has another winter starting in three weeks.
If the screwdriver test came back clean and the floor is sound, this is the cheap version of this job. Nothing to repair, just grind and coat. It gets more expensive every winter you leave it.