Quick answer: to compare epoxy quotes fairly, write the scope yourself before you ask anyone to price it, send the same sheet to three contractors, and then line up what they return on prep method, film thickness, number of coats, flake coverage and topcoat chemistry. Epoxy quotes differ because the scopes differ. Once the scopes match, the spread usually shrinks a lot.
The step most buyers skip is the first one. A contractor who gets a phone call and a photo will price what they assume, and each assumes something different. Our epoxy garage floor work in Denver starts with a site visit and a written scope for exactly this reason. This post gives you the tools to run the same process yourself: a seven-line specification to send out, a normalization table for the answers, the allowances that hide in the fine print, what a site visit should cover, and the payment terms that are normal in this trade.
Why Three Quotes for the Same Floor Can Differ by a Factor of Three
Quotes differ by that much because the work behind each price is different, and the biggest differences sit in the part of the job you cannot see once it is finished. Prep and film thickness are hidden under the topcoat, so they are the first places a low price saves money.
| Scope Element | Thin Quote Often Includes | Full Quote Often Includes |
|---|---|---|
| Surface prep | Wash and acid etch | Diamond grinding to a measured profile |
| Crack and joint work | Not mentioned | Routed, filled and leveled |
| Moisture check | None | Tested, with a recorded result |
| Build | One coat | Primer or base coat plus build coat and topcoat |
| Thickness | Not stated | Total dry film thickness stated in mils |
| Topcoat | Standard epoxy | UV-stable topcoat such as polyaspartic |
Two further things widen the spread. One is crew type, since a quote that assumes in-house labor and one that assumes a subcontractor carry different overhead. The other is warranty, because a written warranty that names its exclusions costs the contractor something to offer. We cover how to vet a contractor in our questions to ask an epoxy contractor guide, so here the focus stays on the quote documents themselves. For how pricing is built and what typical totals look like, see our epoxy flooring cost guide. This post does not repeat those numbers, because a price means little until the scope behind it matches.
Write the Scope Before You Ask: The Seven Lines to Send Every Bidder
Send each bidder the same seven lines, because a shared written scope is the only way to get prices that can be compared. It takes about ten minutes to write and removes most of the guessing from the quotes.
| # | Line | Example Wording |
|---|---|---|
| 1 | Area and layout | Two-car garage, measured square footage, one photo of each wall, door and drain location |
| 2 | Slab condition you know about | Age of slab, existing paint or sealer, oil stains, cracks, any past water problems |
| 3 | Prep method required | Diamond grinding to a concrete surface profile of CSP 2 to 3, no acid etching |
| 4 | System build | Number of coats, minimum total dry film thickness in mils, flake coverage and size |
| 5 | Topcoat | UV-stable topcoat, product named, gloss level |
| 6 | Repairs and moisture | Crack and joint repair included, moisture test method and result recorded |
| 7 | Schedule, warranty and payment | Start window, return-to-service times, written warranty terms, payment schedule |
Line 3 deserves a note. CSP is the concrete surface profile scale from the International Concrete Repair Institute (ICRI Guideline 310.2R), which runs from CSP 1 for acid etching up to CSP 10, and a garage system typically wants a profile in the CSP 2 to 3 range. Diamond grinding can reach it. Acid etching generally cannot, which is why it is a flag when a quote offers it as the only prep. Line 4 matters because a stated minimum thickness can be checked, and a vague "multi-coat system" cannot. Our own residential specification uses 15 to 18 mils total for a standard garage and a minimum of 20 mils for heavy-vehicle garages, and you can use those as reference points when you fill in your sheet.
Ask every bidder to answer against the same numbered lines. A quote that skips a line has told you something, and you can follow up on that line alone.
Normalizing What Comes Back: Prep Tier, Mil Thickness, Coats, Flake, Topcoat
Normalize by copying each quote into one table, row by row, and marking every blank, because a blank is an assumption you have not agreed to. Do this before you look at the totals. Price is the last column for a reason.
| Row | What to Record | Why It Matters | Flag |
|---|---|---|---|
| Prep tier | Grind, shot blast, etch, or unstated | Sets how well the coating bonds | Etch only, or no method named |
| Profile | CSP number or "not specified" | Can be checked on site | No number given |
| Coats | Primer, base, build, broadcast, topcoat | Each layer has a job | "Epoxy coating" with no layers listed |
| Total thickness | Mils dry film, minimum | Thin films wear and telegraph defects | No mil figure |
| Flake | Full broadcast to rejection, partial, or none | Changes both look and texture | "Flake" with no coverage stated |
| Topcoat | Chemistry and product name | UV stability and abrasion resistance | Standard epoxy, or no topcoat |
| Slip resistance | Additive or texture, any test reference | Garages get wet | Nothing stated |
Two terms cause trouble. "Full flake" and "partial flake" are not standardized, so ask whether the flake is broadcast to rejection, meaning scattered until no more sticks, or sprinkled lightly. Slip resistance can be described by the dynamic coefficient of friction method in ANSI A326.3, and you can ask whether the proposed finish has been tested to it. Do not expect a number for every system, but a contractor who has thought about it will say how traction is achieved.
After the rows are filled in, bring the quotes to the same specification. If one contractor includes grinding and another does not, ask the second what grinding would add. Now you are comparing prices for the same floor, and a spread that looked like a factor of three often narrows to something you can explain line by line. Our guide to choosing epoxy flooring contractors in Denver covers who to invite in the first place.
Allowances and Exclusions: Crack Repair, Moisture Mitigation, Grinding of Old Coating
Allowances and exclusions are where a low quote recovers its margin, so read what each quote leaves out as carefully as what it includes. An exclusion is not a trick, because some conditions cannot be known before the work starts, but it should be stated with a price attached.
| Item | Ask the Contractor | Good Answer |
|---|---|---|
| Crack and joint repair | Is it included, and how many linear feet? | Included up to a stated length, with a rate beyond it |
| Control joints | Filled, or left open? | Method stated; open joints are usually filled with a semi-rigid material |
| Moisture testing | Which method, and who decides the limit? | ASTM F2170 or F1869 named, limit taken from the coating data sheet |
| Moisture mitigation | What happens if readings are high? | A priced mitigation option, not a surprise |
| Old coating removal | Is grinding off paint or an old sealer included? | Included, or priced per square foot after a bond test |
| Oil contamination | Is it treated before coating? | Yes, with the method named |
The two moisture standards measure different things. ASTM F2170 uses probes placed in the slab to read relative humidity inside it. ASTM F1869 measures vapor emission at the surface with calcium chloride, and it is not suitable for lightweight aggregate concrete. Neither one sets a universal pass limit, since the coating manufacturer sets the number for its own product. A quote that says "moisture tested" without naming a method or recording a result has not told you much. Our guide to testing slab moisture before coating explains the numbers.
Where an old coating is present, adhesion is the question. A pull-off test, the method behind ASTM D4541, measures how strongly a coating holds to its substrate. Most garage jobs do not need lab testing, but a contractor who proposes coating over an old layer should be able to explain how they know it is sound.
What a Site Visit Should Cover, and What a Quote Given Without One Is Worth
A site visit should cover everything a photo cannot show, and a quote given without one is an estimate with a price tag on it. For a bare, new slab a phone quote can be close. For anything older, the visit is where the real scope appears.
| Visit Item | What the Contractor Does | Why a Photo Cannot Replace It |
|---|---|---|
| Slab surface | Checks hardness, laitance, existing coating and dusting | Condition is felt and scratched, not seen |
| Cracks and joints | Measures and maps them | Width and movement are hard to judge in a picture |
| Moisture | Runs a test or plans one | Dry-looking slabs can still emit vapor |
| Contamination | Looks for oil and chemical staining | Old oil often shows only after grinding |
| Drainage and slope | Checks floor drains and low spots | Ponding changes the system |
| Access and conditions | Notes door height, power, temperature, vehicles to move | Affects schedule and cure |
A firm price given sight unseen will usually be paired with change-order language, so read for phrases like "price subject to site conditions." That is not wrong, but it means the number is provisional. In Denver, one condition deserves a specific question: cold weather. Temperature affects cure, so ask how the contractor handles a garage that cannot be heated. The site visit is also the moment to get everything written down. If a contractor says it verbally, ask them to put it in the quote. We do not charge a deposit to get a quote, and you should not pay one for an estimate from anyone.
Payment Schedule, Deposit and Change Order Terms That Are Normal in This Trade
A deposit of roughly a quarter to a third of the contract, covering materials, with the balance due on completion is a common structure in this trade. Be cautious about any contractor who asks for most of the money before the work begins, and get the schedule written into the contract.
| Term | Common Practice | Be Cautious When |
|---|---|---|
| Deposit | About one quarter to one third, for materials | Most of the price is due before work starts |
| Balance | Due on completion and walkthrough | Due before the floor is finished |
| Change orders | Written, priced and signed before extra work | Extra work is done on a verbal okay |
| Warranty | Written, with scope, length and exclusions named | Verbal only, or no exclusions listed |
| Cure and return to service | Stated times for foot traffic and vehicles | No times given |
| Quote validity | A stated period | No expiry and no scope detail |
Change orders deserve a sentence of their own. Any work that falls outside the written scope should be priced and signed before it happens, and the quote should say how extra crack repair or grinding is charged, per linear foot or per square foot. Ask for that rate at quote time, while you still have three bidders to compare it across. Then compare the finished sheets, pick the contractor whose scope is most complete rather than whose price is lowest, and ask the others whether they would revise their quotes to match it. If you want us to price your floor against the same sheet, request a quote and send it along.
Frequently Asked Questions
Three is the useful number. One gives you no reference, two tends to split the difference, and more than three rarely adds information. What matters more than the count is that all three price the same written scope.
Almost always prep and thickness. A quote that includes diamond grinding, crack repair and a three coat system at twenty mils cannot be compared with one that includes a wash, an etch and a single coat. Normalize the scope and the spread usually shrinks a lot.
For anything beyond a bare, new slab, yes. Slab moisture, existing coatings, cracks, oil contamination and drainage all change the scope, and none of them are visible in a photograph. A firm price given sight unseen will come with change orders.
A deposit in the range of a quarter to a third of the contract covering materials is common, with the balance on completion. Be cautious about paying the majority up front, and get the payment schedule written into the contract rather than agreed verbally.
You can, but ask what they would remove to get there rather than asking for the same scope cheaper. The honest answer is usually a thinner build, a lighter prep tier or a cheaper topcoat, and then you can decide whether that tradeoff is one you want.