Concrete Repair & Prep in Rochester, MN
Every coating failure we get called to fix failed in the same place: underneath. Epoxy does not forgive bad prep — it telegraphs it, then peels off it. Concrete repair and prep is therefore not a line item we bolt onto coating jobs; it is the first half of every job we sell, and it is also work we price on its own when a floor is being readied for coating.
The core of prep is diamond grinding: the surface layer of the slab — weak, contaminated, or sealed concrete that no coating can hold — comes off, and the fresh, open concrete under it is what the base coat bonds into. Acid etching, the DIY substitute, is not the same thing and we do not pretend otherwise: it cleans the top of the slab; it does not profile it.
Repair is the other half. Cracks are routed out, filled with the right filler for whether the slab is still moving, and ground flush. Spalls and pitted areas are patched and profiled to match. Old paint, sealer, and failed DIY kits come off with the grinder — coating over a failing layer gives the new floor something weak to hold, and the failure just changes its return address.
On a coating job, heavy repair typically adds $300 to $800 to the work — the calculator's repair figure — and it is always named in the written estimate before the job starts, never discovered on your invoice. Standalone prep and repair is priced at the measure, by the floor's actual condition.
The measure itself is part of the service: moisture testing, a hardness and contamination check, and an honest read on whether the slab should be coated at all. Some slabs — active moisture failure, structural movement, oil soaked in for thirty years — get a 'not yet' or a 'no' from us, in writing, free.
What Good Prep Looks Like
A prepped slab is uniformly open and textured — no shiny sealed spots, no paint ghosts, no soft patches — and it drinks a drop of water evenly instead of beading it. That is the surface a high-solids coating can key into, and it is verifiable with your own eyes before a drop of epoxy is mixed.
We show you the slab after grinding, before coating, whenever you want to look. Prep is the part of the job most companies would rather you not inspect; it is the part we would most like you to.
Why Not Just Coat Over It?
Because a coating is only ever as strong as the weakest layer under it. Paint peels and takes epoxy with it; sealer sheds it; oil-soaked concrete rejects it spot by spot until the floor looks like a map of the problem. Every one of those floors gets ground and redone eventually — the only question is whether the grinding happens before your first coating or after your second bill.
The same logic runs the other way: sound concrete with honest prep is why our floors carry the cure schedule and the expectations they do. Prep is not overhead. Prep is the product.
How much does concrete prep and repair add to a coating job?
On a coating job, heavy repair or old-coating removal typically adds $300–$800 — that is the repair figure built into our calculator. Light crack work inside a normal slab is part of standard prep and does not move the band.
Can you remove my failed DIY epoxy kit?
Yes — it comes off with the grinder as part of prep, and it is the most common rescue job we do. What is under the kit decides the rest of the conversation: usually sound concrete that was never profiled, which is exactly the fixable case.
Do you repair concrete without coating it?
We price standalone crack, spall, and grinding work at the measure when it is part of getting a floor ready — for our coating or honestly assessed for someone else's. What we do not do is structural concrete work; if the slab itself is failing, we will tell you and point you at the right trade.
How do I know if my slab has a moisture problem?
We test it at the free measure and show you the readings. The home version of the test: tape a square of clear plastic tight to the slab for a day — condensation under it means vapor is moving through your concrete, and your coating plan needs a moisture-mitigating primer in it.
Ready to price your floor? The measure visit is free — and the price comes in writing.