Concrete Repair and Floor Prep Johnson City TN

What this service is — and what it isn’t

This page covers cosmetic and coating-prep concrete repair: the surface-level work needed to turn a damaged garage, shop, or basement floor into a sound substrate for an epoxy or polyaspartic coating. That covers cracks, spalls, pop-outs, pitting, joint damage, and surface roughness — the 90 percent of concrete damage that actually walks through a coating quote process.

What this service is not: structural concrete work. If your slab is sinking, you have a foundation crack from settling, you need a driveway leveled, or a section of floor needs to be poured fresh, that’s a different trade and you’ll hear so on the site walk. There are good structural concrete and mudjacking contractors in the Tri-Cities for that work. Nothing is more wasteful than coating over an unresolved structural problem — the coating telegraphs every movement of the slab underneath and fails in months.

The page below covers what actually gets fixed, what it costs, and the diamond-grind prep that runs on every coating job regardless of how good the concrete looks.

Damage types repaired before coating

These are the conditions most often found on Johnson City and Kingsport garage and shop floors, in rough order of frequency:

Hairline and narrow cracks (under 1/8 inch)

The most common condition in residential Tri-Cities garages — thin shrinkage cracks that have been there since the slab cured. Each crack gets chased with a diamond crack-chaser blade to open it to a uniform width (about 1/4 inch), then filled with a polyurea joint filler. The filler cures rubbery, flexes with slab movement, and the coating bridges over it cleanly. Done right, these cracks vanish under the finished floor and don’t telegraph back through.

Wider cracks and active cracks (1/8 to 1/2 inch)

Wider cracks get the same treatment — chase, clean, fill with polyurea — but the crack is also checked for “active” movement by comparing width at the slab edges to width at the middle. Active cracks (still moving with seasonal temperature changes, common in the Tri-Cities where freeze-thaw cycling is heavier than lower East Tennessee) get a slightly more flexible filler and sometimes a fiberglass reinforcing mesh tape under the coating in that zone. Cracks over a half inch wide with vertical displacement (one side higher than the other) usually indicate structural movement and get flagged for a different contractor.

Spalling, pop-outs, and surface flaking

Spalling is where the top quarter to half inch of concrete is flaking off in patches — usually caused by salt damage, freeze-thaw cycles, or a poor original pour. Northeast Tennessee garages see a lot of this from road salt tracked in over winters. The spalled area is ground back to sound concrete, a bonding primer is applied, and the patch goes in with a fiber-reinforced polymer cement mortar. The patch cures in 24 hours and is ground flush before coating.

Pitting and surface roughness

Pitted floors with small craters and pop-outs across the surface are repaired with a thickened epoxy mortar troweled into the pits and scraped flush. For floors with heavy pitting across more than 20 percent of the area, the whole slab gets a skim-coat of self-leveling polymer cement before grinding — costs more but produces a noticeably flatter finished floor.

Failed control joints and saw cuts

Most garage slabs across the Tri-Cities have intentional saw-cut control joints to direct where the concrete cracks as it cures. By 15 to 20 years in, those joints often spall along the edges or fill with debris. They get cleaned out with a joint-cleaning blade, the edges are re-squared, and the joint is filled with polyurea — same product as the crack fill. The coating runs continuously across the filled joint, but the joint is still doing its job underneath.

Oil stains, paint overspray, and old coatings

Surface contamination doesn’t structurally damage the slab but it does prevent a coating from bonding. Oil stains get treated with a degreaser plus mechanical scrubbing; deeper oil penetration gets ground out completely. Old paint and prior failed coatings are removed by shot-blasting or aggressive grinding — there’s no shortcut and no coating that “bonds through” a failing paint layer.

What won’t be coated (honest scope)

Some conditions can’t be solved by surface repair and they’ll be called out on the walk:

Sinking or settling slabs. If sections of your floor are visibly lower than others, the slab needs to be lifted (mudjacking or polyurethane foam) before any coating goes on. Referrals to Tri-Cities concrete lifting contractors are available.
Active foundation cracks. A crack that runs from a wall into the floor and is still moving is a structural issue, not a flatwork issue. Same referral.
Slabs with unresolved moisture intrusion from below. If groundwater is wicking up through the slab (visible as efflorescence, dark damp patches, or repeated moisture-meter spikes), no coating will hold long-term until the moisture source is addressed. This is especially common in older Carter County and Washington County basements built into hillsides.
Concrete poured within the last 28 days. New concrete is still curing and gassing off moisture. Anything coated before full cure delaminates inside the first year.

Walking away from the wrong job is part of why the coatings that do get installed actually last.

Diamond-grind surface preparation

Every coating job starts with diamond grinding the entire floor, not just the damaged areas. This is the single most important step in the process and the one most often cheaped out by lower-end installers.

What diamond grinding does: a counter-rotating grinder fitted with diamond-segment tooling removes the laitance (the weak, dust-prone top layer of cured concrete), opens up the surface porosity, and creates a controlled mechanical profile that the coating physically anchors into. The industry-standard target profile for epoxy is CSP-2 to CSP-3 (Concrete Surface Profile per the International Concrete Repair Institute), roughly equivalent to the texture of 60- to 80-grit sandpaper.

Why acid etching is not used: acid etching with muriatic acid is the budget shortcut competitors use. It creates a profile of CSP-1 at best, doesn’t remove surface contamination, leaves chloride residue that interferes with adhesion, and produces a waste stream that’s not safe to send down a Johnson City storm drain. A coating over acid-etched concrete typically fails 3 to 5 years sooner than the same coating over a diamond-ground floor.

Dust extraction: HEPA-rated vacuum systems run on every grinder. Diamond grinding without dust extraction fills a garage with silica dust at OSHA-actionable levels and coats every surface in white powder. Customer-friendly grinding means HEPA extraction at the grinder, period.

Moisture testing after grind: calcium chloride or relative humidity probes go on slabs at risk for vapor transmission — most Tri-Cities basements, any slab-on-grade in a humid Northeast Tennessee summer, and any garage without a known history. Slabs above 5 pounds per 1,000 square feet per 24 hours get a vapor-mitigating primer before the coating goes down. Coating a wet slab is the second-most-common cause of failure after skipping the diamond grind.

What concrete repair and prep cost in the Tri-Cities

Installed pricing for Johnson City, Kingsport, Bristol, and the surrounding region, separated out so you can see what the prep portion of a quote is actually costing:

Hairline and narrow crack repair (polyurea fill, chased): $3 to $6 per linear foot of crack
Wider crack repair with reinforcing: $6 to $12 per linear foot
Spalling and pop-out patching: $4 to $10 per square foot of damaged area
Pitting fill (epoxy mortar): $2 to $5 per square foot of pitted area
Full skim-coat for heavily pitted floors: $3 to $6 per square foot of total floor
Failed control joint cleanup and refill: $4 to $8 per linear foot
Diamond grinding (standard prep, included in every coating job): $1.50 to $3 per square foot — about 25 to 35 percent of the total installed coating price
Vapor-mitigating primer (when moisture test fails): $1.25 to $2.50 per square foot of treated area
Removal of failed existing coating before new install: $1.50 to $3.50 per square foot depending on coating thickness

On a typical 2-car Johnson City garage (about 450 square feet) with a handful of hairline cracks, a few small pop-outs, and one failed control joint, repair work usually lands in the $300 to $600 range on top of the coating price. Heavily damaged shop floors with widespread spalling and pitting can run $1,500 to $3,000 in repair before any coating goes down.

Why prep is what makes the coating last

A 3-year-old failed epoxy floor in Johnson City is almost never the product’s fault. Modern 100% solids epoxy and polyaspartic resins from real manufacturers (Penntek, Citadel, Elite Crete, ArmorPoxy, Roll-On Rock) are mature, well-tested chemistry — they don’t spontaneously fail. What fails is the bond between the resin and the concrete underneath. And that bond is determined by prep.

The three most common failure modes seen on replacement jobs, in order:

Coating delaminated in sheets. Almost always means the original installer acid-etched instead of diamond grinding, or didn’t remove a prior coating fully. The new coating bonded to the old coating instead of to the concrete, and the whole stack lifted together.
Coating bubbled or blistered after 6 to 18 months. Moisture transmission from below. The installer skipped moisture testing or skipped the vapor-mitigating primer. Common in Tri-Cities basement installs done in summer.
Coating peeled along cracks and control joints. Joints and cracks weren’t properly filled with polyurea before coating, so the coating stretched and split as the slab moved with seasonal temperature swings.

All three failures cost more to remediate (rip-out plus reinstall) than a properly prepped job would have cost the first time. That’s why corners don’t get cut on prep, and why the coatings installed up here carry their full manufacturer-backed warranties.

Our process

On-site walk. A real look at the concrete — photographs of the damage, a quick moisture-meter check, questions about the floor’s history (when it was poured, prior coatings, water issues). Free, no obligation.
Written scope and quote. Repair work, prep work, and the coating system are itemized separately so you can see what each line costs. If the floor needs structural work first, you’ll hear that on the walk and get referred out.
Day 1, morning — repair. Crack chasing, spall patching, pitting fill, joint repair. Most residential garages get all repair work done in 2 to 4 hours.
Day 1, afternoon — cure window. Polyurea fillers cure in 30 to 60 minutes; epoxy mortar in 4 to 6 hours; cement-based patches in 24 hours.
Day 1 or Day 2 — diamond grind. Full-floor grind to CSP-2 to CSP-3 profile with HEPA dust extraction. Moisture testing on at-risk slabs.
Coating install. Per the system spec in your written quote — see the garage floor epoxy, polyaspartic, metallic, or commercial & industrial pages for the system that fits your floor.

Get a concrete repair and prep quote in the Tri-Cities → (423) 726-7343

Frequently asked questions

How much does it cost to repair concrete?

For Tri-Cities residential garage floors, concrete crack and spall repair runs roughly $0.75 to $2.50 per square foot of floor area on top of any coating price. A typical 2-car garage with a handful of hairline cracks and a few small pop-outs lands in the $300 to $600 range for repair. A garage with deep cracking across most of the slab, significant pitting, and failed control joints can run $1,200 to $2,000. Standalone diamond grinding (just the prep, no repair) is $1.50 to $3 per square foot. We quote repair as a separate line item from coating so you can see exactly what the prep is costing instead of having it buried.

Can I pour concrete over old cracked concrete?

Pouring a fresh overlay over cracked concrete is almost never the right call for a coating project. New concrete takes 28+ days to cure enough for coating, has higher moisture content during that window, and creates a worse substrate than properly repaired old concrete because the laitance (the weak surface layer) has to be removed anyway. What we do instead: chase the cracks with a saw or diamond crack-chaser blade, fill them with semi-rigid polyurea joint filler (the same product used in commercial warehouses), cure, then grind the surface flush. The repair becomes a structural part of the slab and vanishes under the coating.

Can you repair damaged concrete?

Most damaged garage and shop floors in the Tri-Cities can be repaired and coated successfully — replacement is rare and usually unnecessary. The categories we handle routinely: hairline and narrow cracks (polyurea fill), wider active cracks (polyurea + reinforcing mesh), spalling and pop-outs (fiber-reinforced patching mortar), pitting (epoxy mortar fill or full skim-coat), and failed control joints (clean + refill). What we walk away from honestly: slabs with active structural movement, foundation cracks running into the slab, unresolved moisture intrusion from below, and concrete poured within the last 28 days. The on-site walk identifies which category your floor falls in.

What is the best product to fix large cracks in concrete?

For large cracks in garage and shop floors that will be coated, semi-rigid polyurea joint filler is the industry standard — the same product used in commercial warehouses. It's poured into the chased crack, cures rubbery, flexes with seasonal slab movement, and bonds to the concrete on both sides. After cure, the surface is ground flush and the coating bridges over it cleanly. For cracks that aren't getting coated (cosmetic repair on exposed concrete), epoxy crack injection or polymer-modified concrete patching mortar are alternatives — both more visible than polyurea fill, but adequate for non-coating scenarios. Hardware-store concrete patch products work for tiny cosmetic fills but routinely fail under any coating.

Do I need to repair concrete before epoxy coating?

If your slab has cracks, spalling, pitting, joint damage, or surface contamination, yes — repair has to happen before coating, or the coating fails at those spots. A coating bridges over a properly repaired crack cleanly; a coating over an unrepaired crack splits along the crack line within a season or two as the slab moves. Significant repair gets quoted as a separate line item from the coating itself so you see exactly what the prep is costing. Light crack-and-joint repair is often built into the base quote. The honest answer for most Tri-Cities garages: yes, some level of prep work happens before coating, but it's usually less than homeowners expect.

Other coatings we install

Last updated: May 24, 2026

Concrete Floor Repair & Prep in Johnson City, TN