To paint a concrete floor, clean and repair the slab, prime it with Clear Bonding Liquid, then apply two thin coats of a floor-grade coating — Concrete Enamel outdoors or 1K Polyurethane for interior traffic. The paint is the easy part; the prep decides whether the floor lasts years or peels in months. Here is the full method.
What you need
Gather the coating and prep in advance: a floor degreaser or sugar-soap, a stiff brush or scrubbing pad, crack filler, Clear Bonding Liquid primer, a floor-grade topcoat, a 100 millimetre (mm) brush for cutting in, and a medium-nap roller on a pole. Choose the topcoat by location: Concrete Enamel for a stoep, patio or open garage, or 1K Polyurethane for an interior workshop or garage under heavy traffic.
Step 1 — Clean the slab
Strip the floor back to clean, bare concrete. Sweep off dust and grit, then degrease oil and tyre marks with a floor degreaser and scrub. Remove any old flaking paint. Rinse and let the slab dry fully — a coating applied over grease, dust or damp will not bond.
Step 2 — Repair cracks and let new concrete cure
Fill cracks and holes with a cement-based filler, and let new concrete cure for about 28 days before painting. A fresh slab still holds moisture and alkalinity that lift a coating. Rake out loose cracks, fill, smooth level, and let repairs dry. Check the floor is dry with the plastic-sheet test: tape a square of plastic down overnight; condensation underneath means the slab is still too wet to paint.
Step 3 — Prime with Clear Bonding Liquid
Prime chalky, dusty, porous or new concrete with Clear Bonding Liquid so the topcoat grips. A concrete floor that dusts when you rub it, or drinks water on contact, needs a bonding primer to stabilise the surface and stop the paint peeling. Rub a test patch: if your hand comes away powdery, prime. Let the primer dry to the touch before the topcoat.
Step 4 — Apply two thin coats
Cut in the edges with a brush, then roll the field in two thin, even coats, letting each dry before the next. Work in one direction and keep a wet edge so the coats blend. Thin coats bond and wear better than one thick coat, which chips at the edges. Budget about 1 litre (L) per 4 to 6 square metres (m²) per coat. Follow the recoat time on the tin — usually 4 to 6 hours at 23 degrees Celsius (°C).
Step 5 — Cure before traffic
Let the floor cure before you use it: light foot traffic after about 24 hours, and full hard-wearing cure over about 7 days. Keep furniture, vehicles and heavy traffic off until the coating has cured, and keep the fresh coat dry from rain. Rushing a floor back into service is a common cause of early scuffing and marks.
How long does it take to paint a concrete floor?
Painting a concrete floor is a weekend job for most rooms: about a day of prep and priming, then two coats over the following day with drying time between. A single garage of about 18 m² is comfortably done over two days. The active work is only a few hours; the rest is drying and curing time you cannot rush. Plan the job for a dry, mild spell so coats cure properly.
Can you paint a concrete floor without priming?
Only if the floor is sound and previously painted; bare, dusty or new concrete must be primed first. A firm existing coat can take a fresh topcoat after a clean and light sand. Bare concrete that dusts or drinks water needs Clear Bonding Liquid, or the new paint peels within months. When in doubt, prime — it is the cheapest insurance on the job.
5 mistakes that make floor paint fail
Most floor-paint failures come down to five avoidable mistakes. They are: 1) using wall paint instead of a floor coating; 2) painting over grease, dust or a damp slab; 3) skipping the primer on bare concrete; 4) laying one thick coat instead of two thin ones; and 5) parking or loading the floor before it has cured. Avoid all five and a painted floor lasts years.
How do you apply floor paint on a garage or stoep?
The method is the same for a garage or stoep: clean, repair, prime, and roll two thin coats. A garage floor takes Concrete Enamel, or 1K Polyurethane for a heavy workshop; a stoep takes Concrete Enamel for its UV resistance. See the best paint for a garage floor and stoep paint.
Where to buy
Shop Clear Bonding Liquid, Concrete Enamel, 1K Polyurethane and the full Floors range with national delivery, or visit our paint shops in Table View, Cape Town and Edenvale, Johannesburg. Trade line: +27 84 985 6141. Start with the floor paint guide.
