Failed DIY Epoxy Floor in Reno, NV

A DIY kit that failed did so for one of two reasons, and the difference decides whether a rebuild is even possible. Either the film failed — 2 to 5 mils thin, rolled onto a slab that was never mechanically prepped, with no moisture test behind it — or the slab was already outside specification before the kit was opened: reading above 5 lbs per 1,000 sq ft per 24 hours on ASTM F1869 or above 75% RH on ASTM F2170, or a new slab under 28 days of cure and under 2,500 psi. Telling those apart is the same peel test a professional starts with: look at what came off with the film, and tap for hollow areas.

How a DIY floor fails, and when

Roller marks and thin edges. Uneven film, heavier in the middle of the bay, thin at the perimeter and the door apron where the film matters most.
Fisheyes and bare patches. Oil, grease and tire dressing left in the top fraction of the concrete repel the resin — mechanical preparation removes them, etching does not.
Peeling at the edges. The perimeter and apron lift first, because that is what a hand-held prep tool never reaches. This is the same failure that appears on a professionally coated floor when the edge detail is skipped.
Blisters in the first hot week. Vapour pushing up through the slab into a rigid film, and the more likely version of it after a Reno July than after a spring install.
Tire-shaped tears in the first summer. A film too thin and too soft to hold under a hot tire, exactly as it would be anywhere.
Timing. Most DIY floors fail inside 24 months. A professional build is expected to run 12 to 15+ years before it needs a topcoat rejuvenation, which is the whole gap in one line.

Why a Reno garage is a hard place to do it yourself

The temperature swing. Mean highs of about 45 °F in January to about 90 °F in July, with records of 108 °F and −16 °F. A rigid kit film lives through all of that on a slab that is moving the whole time.
The slab underneath. This is the part a kit cannot know. Truckee series soils under the flood-plain ground hold a seasonal water table at 50 to 100 cm and stay saturated three or more months in most years; Reno series soils on the alluvial fans have a duripan at 50 to 100 cm and low saturated hydraulic conductivity, so water perches instead of draining. Both scenarios push vapour at a film that was never tested for.
No profile. A resinous system needs ICRI CSP 3 to 4 — a measurable roughness. Etching a slab by hand is unpredictable and unverifiable, and it cannot reliably get there. The result is a coating bonded to laitance, which is bonding to powder.
No barrier. Where the readings call for it, a moisture vapor barrier primer goes below the base coat, and it needs its own cure time. A single-day kit run has no such layer.
The cure window. Traditional epoxies cure slowly, over roughly 12 to 18 hours, and they set hard as they do. For most of a day the film is soft enough to take vapour into the resin, and a Reno garage heats up fast in the morning sun.
Then it has to come off. The failed kit is not a surface you can coat over. It is a layer that has to be ground off before a proper system can be installed, which is why a failed DIY floor usually costs more to put right than a bare slab would have.

What a pro checks before redoing it

How far the film has released. Tap test across the field and the tire lanes to map it. A film that is still bonded may be ground back and rebuilt over; one that is lifting in sheets all comes off.
Moisture readings on the slab. ASTM F1869 at 5 lbs per 1,000 sq ft per 24 hours and ASTM F2170 at 75% RH, taken at the worst spot on the floor. This is the step that decides whether the rebuild includes a moisture vapor barrier — and it is the step the kit skipped.
Cure and strength on a newer slab. 28 days from placement and 2,500 psi minimum. On a slab under 28 days, the correct answer is to wait, not to coat.
A grind test patch to see what comes up and what profile the concrete will hold, plus a check on contaminant areas where oil has soaked in.
Preparation to a CSP 3 to 4 profile with the edges, corners and door apron brought to the same standard as the field — shot blasting for the open slab, planetary and hand grinders for the detail work, and dust extraction at the tool so the work is not done in a silica cloud.
A written specification that names the layer count, the dry film thickness the system will finish at, and whether a moisture vapor barrier is included. Two quotes that look alike on one page are not the same job if one of them leaves the barrier out.

The 12-year arithmetic, and what it costs

The upfront comparison always favours the kit. The comparison that matters runs longer.

Line	DIY kit	Professional system
Upfront	$60 to $160 per kit, and a 2-car garage takes more than one	$5.00 to $15.00 per square foot, or $2,500 to $6,000 for a 2-car garage
Dry film thickness	2 to 5 mils	20 to 35 mils
Failure timeline	Inside 24 months	12 to 15+ years before a topcoat rejuvenation
Repeat materials over 12 years	$720 to $1,920	$0 repair cost
Labour	Continuous scraping, stripping and recoating	Sweeping and mopping

Flake systems run $3 to $8 per square foot and polyaspartic systems $5 to $9 per square foot inside that professional band. When you compare a quote against the kit price, add in the second kit, the etching acid, the grinder you may end up renting, and the stripping of the old film. That is the number the store shelf never shows.

Frequently asked questions

Can a failed DIY epoxy floor be coated over?

Not reliably. The failed film is now the weakest layer, and a new coating bonds to it rather than to the concrete, so it leaves with it. The usual scope is to grind the old film off to a CSP 3 to 4 profile and build a system from the slab up — with moisture testing first, because the kit never did it.

Why did my epoxy kit peel within a year when the label promised years of life?

Because the label describes the coating and not the slab. A kit film finishes at 2 to 5 mils, it relies on hand etching rather than a measurable CSP 3 to 4 profile, and it does not include moisture testing or a vapor barrier. Failures inside 24 months are the norm on a thin film over an untested slab in a climate with a 45 °F to 90 °F swing.

Is it cheaper to redo it myself a second time?

Run the 12-year numbers before deciding. A kit costs $60 to $160 and a 2-car garage takes more than one, recurring materials run $720 to $1,920 over 12 years, and the DIY route has to strip and re-roll the floor repeatedly. A professional system is $5.00 to $15.00 per square foot, lasts 12 to 15+ years, and carries $0 repair cost over the same window — which is why the two lines usually cross well inside the 12 years.