Crack repair is not permanent, and a coated floor can still crack

Say the honest part first

We repair cracks before we coat. We open them out, fill them with a rigid polyurea or epoxy filler that cures harder than the concrete around it, and grind it flush. Done properly, that repair is strong, it holds, and on most floors it stays put for the life of the coating.

What nobody can promise is that it is permanent. If the slab moves again, the crack comes back, and it comes back through whatever is on top of it. That is true of our coating, every other coating on the market, tile, paint and anything else you put on concrete.

Why concrete cracks in the first place

• It shrinks as it cures and keeps shrinking slowly for years. That is where most hairline cracking comes from, and it is normal.
• The ground under it moves. Clay soil in this area swells when wet and shrinks when dry. Frost heaves it in winter. A slab sitting on that moves with it.
• It expands and contracts with temperature. A garage slab in Illinois sees a swing of well over a hundred degrees across a year.
• Control joints are there on purpose. They are a deliberate weak line so the slab cracks where you planned instead of randomly. A joint is not a defect, it is a design feature, and a joint that is filled solid can force the slab to crack somewhere else instead.
• Loads and roots and settling. A heavier vehicle, a tree root, a washed-out base.

None of that stops because a coating went on top. A coating is roughly the thickness of a credit card. It is not structural and it never was.

What this means practically

• A filled crack is a cosmetic and functional repair on a line that may still be alive. It seals it, levels it and hides it. It does not weld the slab back together.
• You will usually still see where it was. Under a heavy flake broadcast a repaired crack is close to invisible from standing height and findable if you go looking from a foot away. Anyone promising it will vanish completely is overselling.
• An old crack that reopens is a concrete event, not a coating failure. That distinction matters because it decides who pays, and it is excluded from essentially every coating warranty in this industry, including ours.
• Some cracks are more likely to come back than others. A hairline shrinkage crack in the middle of a sound slab usually stays fixed. A crack with one side sitting lower than the other, a crack that runs the full width of the slab, or one that has visibly moved over the years is telling you the ground is still working. We will say so when we see it.

What we actually promise

Our written 10-year warranty covers our workmanship: adhesion, peeling, delamination, bubbling and flaking caused by how we installed the floor. If the coating releases around a crack we repaired, that is ours and we fix it.

It does not cover the slab itself. New cracks, old cracks reopening, settlement, heaving and substrate failure are concrete problems. We cannot warranty the earth under your house and nobody honestly can. See what a coating warranty really covers for the full list of exclusions, in plain language, on purpose.

What we do to give a crack the best chance

1. Read it before we quote. Width, whether the two sides are at different heights, whether it continues up a wall or out into the driveway. That tells us whether we are looking at shrinkage or movement.
2. Chase it out. A crack gets opened into a V or a U so the filler has real material to key into, rather than being smeared over a hairline.
3. Use the right filler. Rigid polyurea for static cracks so it can be ground flush and carries the load. A flexible joint sealant where the line needs to keep moving.
4. Respect control joints. We decide per floor whether a joint gets honored and carried through the coating or filled, because filling every joint solid can cause a new crack elsewhere.
5. Specify flake, not solid color. Heavy flake breaks up the eye and hides a repair dramatically better than a single color does. On an old slab this is the difference between a floor that reads as new and one that reads as patched.
6. Tell you the risk out loud and note it on the quote where we think a specific crack may come back.

If a crack does come back

Call us. In most cases we can open that line, repair it again and spot recoat. A repair on a floor that is a few years old will not be a perfect color match, and we will tell you that before we do it rather than after. It is still far better than living with an open crack collecting water and salt.

Related: can a pitted, cracked floor be saved and can a coating level a floor.

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