Floor coating has a low barrier to entry. A grinder, a van and a website is enough to start, and quality in this trade varies more than in almost any other home improvement.
The good news is that the difference between a good contractor and a poor one shows up quickly in conversation, because the things that matter are specific and technical.
1. How are you preparing the slab?
The answer you want: diamond grinding, or shot blasting on larger commercial areas.
The answer that should worry you: acid etching, chemical preparation, or pressure washing.
This is the single most important question on the list. A coating bonds to concrete by keying into an open, profiled surface. Acid etching opens it unevenly and leaves residue behind, so the coating grips in patches. It looks identical on day one and comes off in sheets in year two, with a clean glossy underside and no concrete attached.
If you ask only one question, ask this one.
2. What system are you putting down, coat by coat?
The answer you want: a named base coat, a broadcast, and a named topcoat. For a Birmingham garage that usually means a polyurea base, vinyl flake, and a polyaspartic topcoat.
The answer that should worry you: "an epoxy floor". That describes an outcome, not a build.
A single-product answer often means a single-coat product, and single-coat products in a garage in this climate do not last.
3. Have you tested the slab for moisture?
The answer you want: either a test result, or a clear explanation of why this slab does not warrant one.
The answer that should worry you: "it will be fine".
Vapour drive through concrete lifts coatings from underneath, and Birmingham has a lot of housing built before vapour barriers were standard. Moisture is also excluded from virtually every warranty in the trade, which means an untested slab is a risk being handed to you quietly.
This matters most on basements, lower levels, hillside lots and anything below grade.
4. Is the topcoat UV stable?
The answer you want: yes, aliphatic.
Standard epoxy is aromatic and yellows under ultraviolet light. A garage with the door open for part of the day gets direct sun on the slab. Any outdoor concrete gets far more.
A contractor who knows the word aliphatic does outdoor work regularly. One who does not, does not.
5. What total film thickness?
The answer you want: a number in mils. A residential garage generally lands around 20 to 30 depending on flake density.
This is a legitimate technical question with a real answer, and it separates contractors who understand what they are installing from those repeating a script.
6. What happens if the slab is worse than it looks?
The answer you want: a defined process. We stop, we show you, we re-quote for the additional work, you decide.
The answer that should worry you: a shrug, or a promise that it will not happen.
Concrete has surprises in it. Old coatings under old coatings, oil that soaked deeper than expected, spalling under a layer of paint. A contractor who has a process for that has hit it before, which is reassuring rather than otherwise.
7. Can I see the warranty document before I commit?
The answer you want: yes, here it is.
Nearly every company here advertises a lifetime warranty, so it does not differentiate. What differentiates is the exclusions. Moisture is almost always excluded, and in a fair number of documents so is hot tyre pickup, which in this climate is a substantial gap.
A company that will not show you the document until after payment is telling you something about it.
Three things that do not matter as much as you would think
Years in business. Useful context, not a guarantee. A four-year-old company grinding properly will give you a better floor than a twenty-year-old one that etches.
Brand of product. Manufacturers matter less than installation. The overwhelming majority of failures in this trade are preparation and moisture, not product.
The lowest and highest price. The cheapest quote usually explains itself in the answer to question one. The most expensive is not automatically better, and it is worth asking what is included that the others left out.
The pressure test
One more, and it is behavioural rather than technical.
Your concrete has been sitting there for decades and it will still be there next week. Anyone insisting you sign today, or offering a discount that expires this afternoon, is selling urgency rather than flooring.
A contractor confident in their work will happily let you get a second quote.
What we would tell you
We would rather say on the first visit that your slab needs a moisture test, or that a densifier and sealer would serve you better than a full coating, or that the concrete has a problem a coating will not solve.
All three of those cost us work and save you money, and the ones that get said before the job are worth far more than anything said afterwards.
For the process on a garage, see garage floor coating. For what happens when it was done badly the first time, repair and recoating.
Common questions
How many quotes should I get?
Two is usually enough if both contractors actually came and looked at the slab. Three quotes where two were given over the phone is worse information, not better.
Should I be suspicious of a one-day install?
Not in itself, because the chemistry genuinely allows it. Be suspicious if it is promised on a floor that needs an old coating removed or moisture mitigation.
Does it matter if they are licensed?
Requirements vary by the scale and type of work. What is more revealing is whether they carry insurance and will show you proof of it.
What if I already have a peeling floor?
Ask why it failed before asking what goes down next. A contractor who cannot diagnose the failure will reproduce it.
Is the cheapest quote always bad?
Not always, but it usually differs on preparation. Ask all of them question one and the gap normally explains itself.
Get a free quote
Tell us the space and roughly how big it is. We'll come measure it, and you get the scope and the price in writing.