What Should You Ask an Epoxy Flooring Contractor?
Ask how they prepare the concrete before coating: diamond grinding to a CSP 2 to 3 profile or shot blasting, not acid etching alone. Preparation determines adhesion and longevity more than any other factor, which is why professional coatings last 5 to 10 years while DIY acid-etched coatings often last 2 to 5. Also ask whether they perform and document moisture vapor emission testing, what specific product system they are installing, how long the cure takes before vehicle traffic, and what warranty covers delamination and peeling. Installed epoxy flooring runs $3 to $12 per square foot.
How Do You Prepare the Concrete Before Coating?
This is the most important question on the list, because preparation determines adhesion and longevity more than any other factor. The correct answer for a professional garage floor system is diamond grinding to the appropriate surface profile (CSP 2 to 3) or shot blasting, both of which mechanically open the concrete for adhesion. Acid etching alone is a thinner preparation, acceptable only for lighter-duty applications, and many lower-cost contractors use it because it is faster and needs less equipment. Diamond grinding physically opens the pores and creates a textured profile that keys the epoxy mechanically; acid etching opens surface pores chemically but produces a less consistent profile and works poorly under the high-build coatings used in professional chip systems. That difference is why professional coatings last 5 to 10 years while DIY acid-etched coatings often last 2 to 5 years. (For more on this, see How to Budget for Epoxy Garage Flooring.)
Do You Test for Moisture, and Can I See the Results?
Moisture migrating up through the slab causes epoxy to bubble and delaminate, and it is the most common epoxy failure mode. Ask whether the contractor performs a moisture vapor emission test before coating, how, and to see the documented results. Professional installers use a calcium chloride test (ASTM F1869) or a relative humidity probe (ASTM F2170) and document what they find. A contractor who cannot show test results either did not test or did not document, and either way the coating is going down over unverified concrete. (For more on this, see How to Find the Best Epoxy Flooring Contractor.)
What Specific System Are You Installing?
Ask for the product brand and full system specification: primer, base coat, chip type and coverage density, and topcoat, along with the chemistry of each (epoxy, polyurea, polyaspartic, or polyurethane). A contractor who can name the products and explain why that topcoat suits your application is installing a specified system. One who refers vaguely to “epoxy” without product specifics may be using inconsistent or lower-grade material from an unbranded source.
How Long Before I Can Park a Vehicle?
Confirm the cure timeline for both foot traffic and vehicle traffic. Coating chemistries cure at different rates, and polyurea and polyaspartic systems cure faster than standard epoxy. Knowing the timeline before you hire prevents parking conflicts after the crew leaves.
What Warranty Covers the Installation?
Ask how long the warranty lasts, whether it covers delamination and peeling specifically, and what the claims process is. Professional epoxy flooring companies typically warrant their installed work for 1 to 3 years, and a correctly installed professional epoxy or polyurea system should carry a labor warranty of at least 2 to 5 years against peeling or adhesion failure. A warranty that excludes delamination, the primary failure mode, is not meaningful protection, and neither is one that covers manufacturing defects only on a product whose performance depends almost entirely on installation quality. Get the terms in writing, stating explicitly that delamination within the warranty period is covered. (For more on this, see Common Epoxy Flooring Mistakes to Avoid.)
Epoxy Garage Flooring Cost at a Glance
| System | Per square foot | Two-car garage (400 to 450 sq ft) |
|---|---|---|
| Basic single-coat epoxy | $3 to $7 | $1,200 to $3,150 |
| Mid-range chip-and-topcoat system | $7 to $10 | $2,800 to $4,500 |
| Premium polyurea or metallic | $10 to $12 | $4,000 to $5,400 |
Ranges here are national ballpark figures, not quotes. Actual pricing varies by region, home condition, materials, and contractor. How we source cost data.
The chip-and-topcoat system is the most popular residential choice; the premium systems cure fastest and offer the best UV stability. Surface preparation, meaning diamond grinding, crack repair, and moisture testing, is the most important cost component, so confirm it is included in any professional quote. Add $200 to $600 for concrete crack and spall repair if the slab needs it. Ask which of those items the bid includes and which are excluded, since a quote that leaves crack repair out will not stay at its quoted number once the grinder exposes the slab.
How to Compare Quotes
Require every quote to specify the same system (product brand, base coat, chip coverage, topcoat chemistry), the same preparation method, and whether moisture testing is included. Large price differences usually reflect preparation differences rather than a better deal: a quote that comes in $500 to $1,000 lower often omits diamond grinding or uses thinner products. Get two or three site-visit quotes on equivalent defined scope, and verify current general liability insurance and workers compensation before anyone starts.
The Question That Reveals the Most
Ask what the most common reason is that projects like yours fail prematurely. A contractor who answers specifically, such as moisture under the floor for an epoxy coating, inadequate base preparation for a driveway, or the wrong spring selection on a garage door, has thought about failure modes and how to prevent them. One who cannot answer clearly, or who says failures are rare without explaining how they avoid the known causes, is focused on closing the transaction.
Get It in Writing Before Work Begins
Document the project in a written contract before work starts: exact scope including materials, preparation method, and specific products, the cost and payment schedule, the timeline, warranty terms for labor and materials, and the process for handling scope changes. For any project over $500, written scope is non-negotiable. Tie payments to milestones, with the final payment after a walkthrough, and be wary of any contractor asking for payment in full upfront. Most disputes trace back to scope items discussed verbally but never confirmed in writing, or warranty coverage the two parties understood differently.
Frequently Asked Questions
Ask how they prepare the concrete (looking for diamond grinding or shot blasting rather than acid etching alone), whether they perform and document moisture vapor emission testing, what specific product system they are installing, how long the cure takes before vehicle traffic, and what warranty covers delamination and peeling.
Diamond grinding physically opens the concrete pores and creates a textured surface profile that mechanically keys the epoxy. Acid etching opens pores chemically but produces a less consistent profile and works poorly under high-build professional chip systems. That difference in adhesion is why professional coatings last 5 to 10 years while DIY acid-etched coatings often last 2 to 5 years.
Basic single-coat epoxy runs $3 to $7 per square foot installed, or $1,200 to $3,150 for a 400 to 450 square foot two-car garage. A mid-range chip-and-topcoat system runs $7 to $10 per square foot ($2,800 to $4,500), and a premium polyurea or metallic system runs $10 to $12 ($4,000 to $5,400).
Ask to see the moisture vapor emission test results before coating begins. Professional installers use a calcium chloride test (ASTM F1869) or a relative humidity probe (ASTM F2170) and document the results. A contractor who cannot show results either did not test or did not document, and both are red flags.
Professional contractors typically warrant installed work for 1 to 3 years, and a correctly installed epoxy or polyurea system should carry at least 2 to 5 years against peeling or adhesion failure. Get it in writing stating that delamination is a covered failure, since a warranty limited to manufacturing defects is not meaningful on an installation-dependent product.
Require every quote to specify the same system (product brand, base coat, chip coverage, topcoat type), the same preparation method, and whether moisture testing is included. A quote that is $500 to $1,000 lower usually omits diamond grinding or uses thinner products.
Confirm the cure timeline for foot traffic and vehicle traffic with your contractor, since it varies by chemistry. Polyurea and polyaspartic systems cure faster than standard epoxy, so ask before hiring to avoid parking conflicts after installation.
Yes. Skipping the test means cutting the step that protects against the most common epoxy failure mode. Standard epoxy applied over a moisture-positive slab will bubble and peel regardless of how well the rest of the installation is done.