Five Things an Estimator Checks Before Anyone Writes Anything Down
Every garage floor coating company on the internet ends with book a free on-site estimate. Almost nobody describes it. Here is what gets tested in your garage, what each result changes, and the questions worth asking while somebody is standing on your slab.
An on-site garage floor coating estimate is five checks and two conversations, and the checks come first because the conversations depend on them. The estimator is trying to answer one question before anything is written down: what does this particular slab need in order to hold a coating for years rather than for a season. A slab in an older Elgin garage that has been painted twice and takes road salt every winter tells a different story than a newer one out toward the county line, and the visit exists to hear it. Below is the sequence, what each result actually changes, and what you should be holding when it is over.
On this page
The short version
Checked: what is already on the slab and whether it is bonded, whether the concrete is giving up moisture, a mapped survey of cracks and joints, the door line and any drain, and the layout with everything that has to move. Asked: how you use the bay. Produced: a written scope you can read straight across against another company's.
What the visit is really for
A coating fails or lasts almost entirely on the condition of the concrete it is bonded to. That is why nobody serious quotes a garage floor from a phone call and a square footage. Two identical two-car bays on the same street can need completely different prep, and there is no way to know which one you own without kneeling on it.
So the visit is diagnostic before it is commercial. The estimator is not there to admire the space. They are there to find the things that would otherwise turn into a change order at nine in the morning on install day, when the cars are already on the driveway and the grinder is already running.
The five checks
1. What is already on the slab, and whether it is still holding on
Bare concrete is the easy case. Most floors are not bare. There is a sealer somebody rolled on when the house was new, a coat of porch paint from a previous owner, or a kit epoxy that went down one summer and started letting go by the following spring. The estimator is checking two things: what the finish is, and whether it is still bonded.
The bond check is physical and unglamorous - working an edge, testing a suspect patch, seeing whether a section lifts with very little persuasion. A finish that is firmly stuck can sometimes be prepared and built over. A finish that releases has to come off, and taking a stubborn old coating off a slab is real work that has to be in the scope rather than discovered later. Our guide to why coatings fail early is largely a catalogue of what happens when this check gets skipped.
2. Whether the concrete is giving up moisture
Concrete is porous, and a slab that is moving water vapor up through itself will push a coating off from underneath no matter how well the top was prepared. The field version of the check is a sheet of poly taped down tight and left alone, which is not a folk remedy but a published test practice - ASTM D4263, the plastic sheet method. Meters get used too, and on a questionable floor a more involved test gets called for.
Note the practical consequence, because it is the one people are not expecting: this check needs time to sit. Some of what the visit decides genuinely cannot be decided while the estimator is standing there, which is why a careful company will leave a test in place, or tell you plainly that the result changes the system.
3. Cracks, joints and spalls, mapped rather than glanced at
Anyone can see that a floor has cracks. The survey is about which ones, where, and what kind. A hairline that has not moved in years is a different line item from a crack with lifted edges, and a control joint is not a defect at all. Spalled and pitted areas get noted by location, because location is diagnostic: damage clustered inside the overhead door of a Kane County garage is usually the tire-borne salt and meltwater story that our piece on freeze-thaw damage lays out.
What this changes is the repair line on your scope. Every one of those defects is time, material, and in some cases a cure window before the coating can go over it.
4. The door line, the threshold, and anything that drains
The overhead door line is the hardest-used strip of any garage floor and the place where a decision has to be made rather than assumed: how far out the coating runs, how the edge is finished, and what happens where the slab meets the apron outside. If there is a floor drain, the estimator looks at how the coating terminates around the body of it and whether the floor still falls toward it.
Slope matters here beyond drainage. A bay that no longer sheds water toward the door holds meltwater in a low spot all winter, and knowing that before install day changes how the floor gets detailed.
5. The room itself, and everything that has to move
Last comes the boring part that decides the schedule: measurements, and an honest inventory of what is in the way. Built-in cabinets, a utility sink, a water heater on the slab, shelving bolted to the wall, a lift, the stairs up into the house, the second refrigerator nobody wants to unplug. The crew has to grind wall to wall, so anything that cannot move has to be worked around and detailed by hand, and anything that can move has to be somewhere else that morning.
What the estimator will ask you
The inspection tells them about the concrete. Only you can tell them about the garage. Expect questions along these lines:
- How the bay actually gets used. Daily drivers, a project car, bikes and a chest freezer, a home gym in the third stall. The use changes the finish decisions more than most people expect.
- What has been done to the floor before. Sealed, painted, patched, ground, coated. Previous owners count.
- Where the water shows up. Which corner stays wet, whether anything drips through from above, whether the slab sweats in spring.
- What is parked on it in winter. Salt-covered vehicles, a snowblower, a plow truck that comes home loaded.
- What the finished floor needs to do - and how much disruption the household can absorb on install day.
What to ask back
This is the half homeowners skip. Somebody who works on concrete for a living is standing in your garage; use them. Good questions to have ready:
- What did you find that I could not see? The most valuable sentence of the visit usually comes out of this one.
- Which of these cracks are you repairing, and which are you leaving alone? There are usually both, and the reasoning is worth hearing out loud.
- What would make you walk away from this slab? An installer who has never turned down a floor is telling you something.
- What in this scope could change once the grinder is running, and how would you handle it? Honest crews name the two or three realistic surprises rather than promising none.
- Where exactly does the coating start and stop? At the door, at the walls, around the drain, up any step.
Questions about warranty terms and how to line one company's paperwork up against another belong to a separate read, and our guide on comparing garage floor coating quotes covers those in order.
What you should be holding at the end
Not a handshake and a promise to email something. A written scope, specific enough to be compared: the prep method named, the coating system named layer by layer, the repairs listed by what they are, how the moisture result is being handled, where the film starts and stops, the warranty terms, and what happens with cleanup. Our breakdown of what belongs in a coating quote is the checklist to hold it against.
What a floor costs is a separate conversation, and one this site deliberately routes to a real look at a real slab rather than a figure - the reasoning behind that is set out where we discuss the factors that move a coating quote. If a home improvement job ever does go sideways in this state, the consumer materials published by the Illinois Attorney General are the place to start, and every one of them assumes you have the scope in writing.
Making the visit worth the trip
Three things, none of them difficult. Pull the cars out so the floor is visible wall to wall. Sweep, or at least clear the corners, because a swept slab reads honestly and a dusty one hides its own damage. And dig out whatever documentation exists - the builder paperwork, a receipt for whatever was rolled on in 2011, photos from before the shelving went in.
Then let the estimator work, and ask your five questions while they do. That is the whole visit. Whenever you want the five checks run on your own concrete, our free on-site estimate is where to start.