Worked case: a two-car flake garage in Sun City, old coating ground off and cracks repaired first — what happens and what it costs

The scenario

Picture a two-car garage of about 400 square feet in a home from an earlier phase of Sun City, the planned community along Interstate 215 where grading began in the early 1960s. The slab is many decades old. Someone rolled a coat of garage paint on it in earlier years, and it has curled at the door and still looks fine at the back wall. Hairline cracks cross the middle of the floor and a few pits sit near the steps, with a dark patch where a car used to stand. The stem wall, the low wall around the room, is bare and dusty.

The household wants a flake floor in a quiet blend, and the finished stem wall and steps are part of the wish. The question is what to do with the old film. A putty knife at the door lifts it in sheets, which says the paint has no grip on the slab, and new coating over it would lift in the same shapes.

The starting conditions at a glance:

• Size: two-car garage, 400 square feet
• Existing floor: an old paint-type coating, peeling at the door and sound at the back
• Slab: many decades old, hairline cracks, pitting and an oil patch
• System: full-broadcast flake epoxy with a clear top coat, stem wall and entry steps included

What the job involves

1. Before any grinding, the installer tests the old film: a putty knife slid under the door-side edge peels it away in strips, so the plan is full removal, not a recoat.
2. Thick or stained spots get a scarifier and the rest a diamond grinder tied to a vacuum; the big door stays up and a box fan pushes dust toward the driveway.
3. An older slab may sit on no vapor barrier and paint can mask dampness, so a calcium chloride kit or in-slab probe reading is taken once the film is gone.
4. Hairline cracks are opened with a router bit, packed with flexible filler and sanded level; pits are patched, and the dark oil patch gets a degreaser and a second grind.
5. With summer heat in mind the crew starts at first light: primer, then a 100%-solids epoxy base in rolled sections, chips broadcast by hand until nothing shows through, and the curb wall and both steps coated the same way.
6. When the base is hard, excess chips are scraped and vacuumed, a clear top coat seals the flakes in, and the product data sheet fixes when feet and cars can return.

Materials and prep

• Diamond-segment grinder plus a scarifier for thick spots, each hooked to a dust vacuum
• Putty knife, a fan and a moisture kit (calcium chloride or in-slab probes)
• Router bit or crack chaser, flexible filler, patch mortar and a sanding block
• Primer, 100%-solids epoxy, vinyl chips and a clear sealing coat
• Roller frames, squeegees, a chip bucket, cleated shoes and painter's tape along the curb wall

Add-ons often paired with this job

• Custom flake blend — +$100–$300. Mixing the flake colors to the household's palette lets the floor coordinate with cabinets and wall paint.
• Extra crack or joint repair (many cracks) — +$150–$450. When the hairlines prove to be a wider network, a flat extra-crack line pays for the added routing and filling.
• Move the garage contents out and back — +$150–$400. Taking shelving and boxes out and returning them afterward is a flat line the household may handle personally.

Why it is done this way

Removal comes first because the problem lives in the old film. A new coating is only as well attached as whatever lies beneath it, and a film that peels at the door will peel again from under fresh flake. The putty-knife test costs nothing and shows which situation the installer is facing.

Flake fits a slab with a past. The chips camouflage the pits and patches that remain after grinding, and the broadcast gives the surface a little tooth. A coated floor can be slippery when wet or oily; flake and a fine grit in the top coat add grip, and a heavier grit adds more and is harder to clean.

Two modifier lines stack here. Minor cracks and pitting add $1–$2 per square foot and coating removal adds $1–$3, lifting the $5–$8 flake base to $7–$13 per square foot over 400 square feet. Listing each line separately lets the household see where every dollar goes.

Midday heat is the quiet scheduling constraint in this part of the Inland Empire: a warm slab shortens pot life, so the crew arrives early and the cars stay on the driveway until the data sheet's return time has passed.

The alternatives that were weighed and set aside:

• Painting over the old film skips the removal line but brings the peeling back.
• Solid color at $3–$6 per square foot costs less and would expose each patch the grind leaves.

What would change the price

• A coating tougher than paint, such as a thick urethane or epoxy build, requires scarifying and raises the removal line.
• A moisture reading over the primer's limit brings in the damp-slab line of $2–$4 per square foot.
• Cracks that are moving, not static hairlines, need a flexible repair and may telegraph back through the coat.
• Switching to a one-car garage of roughly 240 square feet shrinks the area, and every per-square-foot line shrinks with it.
• A crumbly or cracked curb wall has to be repaired before it can be coated.