Which paint should I use on a floor?
Which paint should I use on a floor?
Two-pack epoxy on concrete after a moisture test and a proper grind; floor-grade varnish or floor paint on timber.
Floor coatings fail from underneath. A ground-bearing slab without an effective damp-proof membrane keeps pushing water vapour upward, and that pressure lifts an impermeable coating off in sheets no matter how well it was applied — which is why a moisture test comes before the paint. Tape a square of polythene down tightly for 24 hours and look for condensation or a darkened patch underneath. Preparation is the other half: a new or power-floated slab is sealed and glassy at the surface, and grinding or acid etching to open the pores is what allows any coating to grip. On timber, the equivalent problems are movement between boards and traffic wear at doorways.
The options, ranked
| Option | Good at | Bad at |
|---|---|---|
| Two-pack epoxy | The hardest, most chemical- and tyre-resistant coating for a garage or workshop slab. | Unforgiving: it needs mechanical preparation, a dry slab, and a pot life measured in minutes. |
| Single-pack polyurethane floor paint | Far easier to apply and adequate for a shed, a utility room or light foot traffic. | Wears through under vehicle tyres and lifts if the slab is damp. |
| Floor varnish or hard-wax oil | The right finish for timber floors; oil is repairable in patches, varnish is tougher overall. | Varnish must be recoated whole once it wears through at doorways. |
| Concrete stain or sealer | Penetrates rather than coating, so it cannot peel. | Limited colour and no build, so it hides nothing. |
Technique that changes the outcome
- Tape a polythene square to the slab for 24 hours and check for moisture before committing
- Grind or etch a power-floated slab; a smooth surface has nothing for the coating to key to
- Vacuum thoroughly — sweeping leaves fine dust that sits between coating and concrete
- Prime with the manufacturer's primer, and mix two-pack products by weight rather than by eye
- Respect the pot life; epoxy that has begun to warm in the tub is already going off
What goes wrong
- Coating a damp slab
- Painting straight onto power-floated concrete
- Applying epoxy below its minimum temperature, where it never fully cures
Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here.
Other paint questions
| For | Use |
|---|---|
| Previously painted wood | Clean it, key it and spot-prime bare areas — and find out first whether the existing paint is oil or water based. |
| Bare wood | Knotting solution on the knots, a wood primer, then your topcoat — and prime end grain twice. |
| Plastic | Any paint, provided an adhesion promoter goes on first — and on polypropylene or polyethylene, the promoter is not optional. |
| Kitchens | A scrubbable acrylic eggshell or satin on the walls — and for cabinets, degrease, prime and use a proper cabinet enamel. |
| Bathrooms | A moisture-resistant acrylic in a satin or eggshell sheen with a mould inhibitor — but ventilation, not paint, is the actual fix. |
| Metal | Remove the rust, apply a rust-inhibiting primer the same day, then an alkyd or a direct-to-metal acrylic. |
| Ceilings | A flat matt emulsion — and if there is a water stain or nicotine, seal it with a shellac-based stain block first. |
| Tiles | Tile paint over an epoxy or adhesion primer on a thoroughly degreased and abraded glaze — and expect a limited life in a shower. |
| Fences | A penetrating stain or fence treatment rather than a film-forming paint — and let new pressure-treated timber weather first. |
| Radiators | A radiator enamel — water-based acrylic ones no longer yellow, which ordinary gloss on a hot surface always will. |
| Exterior masonry | A breathable mineral or masonry paint — and on an old solid wall, breathability matters more than any durability claim. |
| Galvanised metal | A mordant wash, a self-etch primer or a purpose-made acrylic primer for galvanising — ordinary oil-based primer peels off in sheets. |
| UPVC | A uPVC-specific paint or an adhesion promoter with an acrylic topcoat — and avoid dark colours, which can distort the frame. |
Common questions
- Which paint should I use on a floor?
- Two-pack epoxy on concrete after a moisture test and a proper grind; floor-grade varnish or floor paint on timber.
- What should I avoid?
- Coating a damp slab Painting straight onto power-floated concrete Applying epoxy below its minimum temperature, where it never fully cures
Related pages
- Which paint goes over previously painted wood? Clean it, key it and spot-prime bare areas — and find out first whether the existing paint is oil or water based.
- Which paint should I use on bare wood? Knotting solution on the knots, a wood primer, then your topcoat — and prime end grain twice.
- Which paint sticks to plastic? Any paint, provided an adhesion promoter goes on first — and on polypropylene or polyethylene, the promoter is not optional.
- Which paint should I use in a kitchen? A scrubbable acrylic eggshell or satin on the walls — and for cabinets, degrease, prime and use a proper cabinet enamel.
- Which paint should I use in a bathroom? A moisture-resistant acrylic in a satin or eggshell sheen with a mould inhibitor — but ventilation, not paint, is the actual fix.
- Which paint should I use on metal? Remove the rust, apply a rust-inhibiting primer the same day, then an alkyd or a direct-to-metal acrylic.
- Which paint should I use on a ceiling? A flat matt emulsion — and if there is a water stain or nicotine, seal it with a shellac-based stain block first.
- Which paint can I use on tiles? Tile paint over an epoxy or adhesion primer on a thoroughly degreased and abraded glaze — and expect a limited life in a shower.
- Which paint should I use on a fence? A penetrating stain or fence treatment rather than a film-forming paint — and let new pressure-treated timber weather first.
- Which paint should I use on radiators? A radiator enamel — water-based acrylic ones no longer yellow, which ordinary gloss on a hot surface always will.
Sources
- Typical range compiled from manufacturer specifications — At One Place