12 Questions to Ask Every Epoxy Contractor Before You Sign

42% of homeowners who hired a flooring contractor in the last two years said they wished they’d asked more questions before signing, according to a 2024 Angi consumer survey. With epoxy flooring specifically, that regret usually shows up 12 to 18 months later — when the floor starts peeling and the contractor’s number goes to voicemail.

The fix is cheap: spend 20 minutes asking the right questions before you commit. A good contractor will answer confidently. A bad one will dodge, deflect, or disappear.

Here are the 12 questions that separate pros from pretenders.

1. What Surface Prep Method Do You Use?

This is the most important question on this list. Everything about a coating’s lifespan depends on surface preparation.

The professional standard is diamond grinding — using rotating diamond abrasives to mechanically profile the concrete and open its pores for maximum adhesion. Shot blasting is equally effective and common on larger commercial jobs. Both create the rough, clean surface that epoxy needs to bond properly.

Acid etching is cheaper and faster. It’s also far less reliable, especially in older concrete, sealed surfaces, or areas with previous coatings. Any contractor who plans to acid-etch your floor is setting you up for a coating that starts peeling within 18 months.

If they can’t give you a straight answer on prep method, stop the conversation.

2. What’s the Solids Content of Your Epoxy?

Solids content tells you what percentage of the product actually remains on the floor after the solvents evaporate. Higher solids = thicker, more durable coating.

• 100% solids epoxy: professional standard, no solvents, maximum film build
• 70–90% solids: acceptable for some applications, less durable
• Under 50% solids: typical of big-box water-based kits — these belong in a utility room, not a garage

Ask specifically: “What’s the solids content of the epoxy system you’re using?” A trained contractor answers immediately. Hesitation means they either don’t know or don’t want you to know.

3. How Thick Will the Finished System Be?

Film thickness is measured in mils (thousandths of an inch). A professional garage floor system should be:

• Primer coat: 3–5 mils
• Color/base coat: 8–12 mils
• Clear topcoat: 3–5 mils
• Total system: 15–22 mils minimum

Thin coatings wear through faster, show scratches sooner, and are more vulnerable to hot tire pickup and chemical damage. If a contractor can’t tell you the target mil thickness, that’s a problem.

4. What Products Are You Using — Manufacturer and Product Name?

“Professional-grade epoxy” is not a product. Push for specifics: the manufacturer name and product line.

Reputable contractors use commercial products from suppliers like Sherwin-Williams, BASF, ArmorSeal, Tennant, or similar industrial coating manufacturers. They should be able to name the exact product without pausing.

This matters because: (a) it lets you look up independent specs and reviews, and (b) a named product comes with a manufacturer warranty that supplements the contractor’s own warranty.

5. How Do You Handle Cracks and Damage Before Coating?

Cracks don’t go away under epoxy. They continue moving with concrete’s natural expansion and contraction — and eventually push through the coating. A good contractor addresses them before applying a single drop of epoxy.

Ask specifically: “If my floor has cracks, how do you handle them?”

Good answers include polyurea crack injection, routing and filling with semi-rigid filler, or surface grinding and patching. Bad answers: “We’ll fill them with epoxy” or “Small cracks aren’t a problem.”

For more on crack repair, see our guide on how to prep concrete for epoxy.

6. Do You Test for Moisture Before You Start?

Moisture vapor transmission is the number one cause of epoxy delamination. Concrete releases water vapor from below — and if that vapor can’t escape through the sealed epoxy surface, it builds pressure and lifts the coating.

A professional contractor tests for moisture using one of two methods: the calcium chloride test (ASTM F1869) or the relative humidity probe test (ASTM F2170). Both require leaving a test kit on the floor for at least 60–72 hours.

A contractor who skips moisture testing is skipping the step that determines whether your floor is even a candidate for epoxy — or needs a moisture mitigation primer first.

7. What’s the Full Cure Timeline?

“Cured” and “dry” aren’t the same thing. Epoxy may be walkable in 12–24 hours and ready for foot traffic in 24–48 hours. But full chemical cure — where the coating reaches its designed hardness and chemical resistance — takes 5–7 days, sometimes longer in cold temperatures.

You need to know:

• When can you walk on it?
• When can you park vehicles?
• When can you place heavy items back?
• What temperature/humidity conditions does cure require?

A contractor who says “you can park your car on it tomorrow” is either using a polyaspartic system (which does cure faster) or giving you bad information that could damage the new coating.

8. Who Actually Does the Work — Your Crew or Subcontractors?

Many flooring contractors sell jobs and then subcontract the installation to whoever’s available. This isn’t automatically bad — but it changes accountability dramatically.

Ask: “Is the crew that installs my floor your direct employees, or subcontractors?” Follow up with: “Will you be on-site during installation?”

If they use subs, ask how those subs are vetted and whether the same crew handles both prep and installation. Inconsistent crews doing different phases is a common source of quality problems.

9. What Does Your Warranty Cover — and What Voids It?

Warranties in the epoxy industry vary from genuine to worthless. Get the terms in writing before you sign.

Key questions:

• Is the warranty from you (the contractor) or the manufacturer?
• What does it cover — peeling, bubbling, delamination, UV yellowing?
• What specifically voids it? (Many warranties are voided by using cleaning products, dragging heavy objects, or anything the contractor can point to after the fact.)
• How do you handle a warranty claim — in writing, and what’s the response time?

See our full epoxy flooring warranty guide for what realistic warranty terms look like.

10. What’s Your Payment Schedule?

The industry standard for a legitimate contractor:

• 25–40% deposit upfront (covers materials)
• Balance due upon completion and your sign-off

Anyone asking for more than 50% before work begins, or full payment upfront, is a risk. The BBB receives hundreds of complaints annually about contractors who collect full payment and then delay, do poor work, or disappear entirely.

11. Can I See Photos of Recent Completed Jobs and Speak to References?

Photos are easy to fake or borrow from online. References are harder to fake.

Ask for two or three references from garage floors specifically, completed within the last 12 months. When you call, ask:

• Did the crew show up as scheduled?
• How long did prep actually take?
• What does the floor look like today?
• Would you hire them again?

One phone call with a real past customer tells you more than 50 five-star Google reviews.

12. What Happens If Something Goes Wrong?

This question reveals character more than competence. A confident contractor answers directly: here’s how we handle warranty claims, here’s our callback timeline, here’s what we do if there’s a problem you didn’t notice during the walkthrough.

A contractor who gets defensive, vague, or pivots to “we stand behind our work” without specifics is telling you they haven’t thought through — or don’t plan to honor — their post-job obligations.

Before You Sign Anything

Run through this list in the first conversation — in person or on the phone. You don’t need to be aggressive about it. Frame it as due diligence: “I have a few questions I’m asking everyone I’m talking to.”

Any contractor worth hiring expects this. They’ll answer quickly and completely because they’ve been asked a hundred times before. The ones who stumble, deflect, or disappear after you ask are doing you a favor by revealing themselves early.

For more guidance on evaluating contractors, see our full contractor-finding guide and our list of red flags to watch for.