Freeze and thaw damage in Edmonton, one crack onward
A single winter can take a crack you could ignore and turn it into a hole you cannot. The mechanism is simple, repetitive and entirely preventable, which is what makes autumn crack work worth booking.
Water finds the crack, then it freezes and expands. That expansion pushes the two faces of the crack apart slightly, and when it thaws the crack is left marginally wider than it was before.
The damage is in the repetition. A region with many crossings of freezing point through a winter does this dozens of times, each one taking a little more, so the crack grows faster than steady cold would ever make it grow.
Then it reaches the base and the failure changes character. Saturated base under traffic loses its structure, and that is how a crack becomes a pothole, how an area settles, and why sealing before winter is the item that prevents the whole sequence.
One winter
The sequence
How a crack in Edmonton becomes a hole
Water enters an open crack
Any unsealed crack is a direct route down. It does not need to be wide, only open, and a hairline is enough to start the process.
It freezes and widens the crack
Expansion pushes the faces apart. Each thaw leaves the crack slightly wider than it was, and a winter provides many repetitions.
Water reaches the base
Once the crack is through, the base saturates. This is the point at which the problem stops being a surface one and starts being structural.
Traffic breaks the weakened area
Vehicles on saturated base push material aside, and what was a line in the surface becomes an edge, then a hole.
Preventing it
Keeping the Edmonton winter out of the surface
Sealing cracks in autumn is the whole answer, and the timing is deliberate. Cracks are at their narrowest after a summer of heat, the surface is dry enough to bond to, and the work is done before the first freeze gets a chance.
Drainage is the companion item. Water cannot be stopped from falling on a surface, but it can be given somewhere to go, and a surface that sheds water has far less of it available to enter a crack.
Spring is the time to look for the damage. Hot rubber sealing is the heavier version for wide cracks, grading is what keeps the water moving, and an annual cycle is how this stops being something you remember too late.
Not cold on its own. It is the repeated crossing of freezing point, because each cycle expands the water in a crack and leaves the crack slightly wider than before.
Enough to turn a crack you could ignore into a hole you cannot, if the crack was open and reached the base. That is the usual story behind a pothole appearing in spring.
Late summer into early autumn. Cracks are at their narrowest, the surface is dry enough to bond to, and the work is finished before the first freeze can use anything still open.
Not properly. The channel has to be dry for the sealant to bond, so winter work either fails to stick or is a temporary measure that needs doing again in spring.
Only partly. A coat slows surface weathering, but it is only a few millimetres thick, and sealer poured across an open crack sinks into the crack rather than bridging it.
New or widened cracks, edges that have broken away, and any area that holds water where it did not before. All three are cheap to deal with at that stage.
