Can You Really Paint a Concrete Patio?

Yes, and for most British patios it is one of the best-value weekend jobs in the garden. A slab that is structurally sound but stained with algae, faded by frost and dotted with moss can be transformed for the price of a tin of masonry paint and a roller. You do not need a contractor, and you do not need specialist kit — just preparation, patience and a decent dry spell.

Be honest about what painting will not fix. If slabs are rocking, the sub-base has failed, or you have large hollow patches that sound dull when tapped, no coating will hold. Hairline cracks and shallow surface damage are fine. Deep movement cracks, crumbling edges and standing water after rain are signs the patio needs re-laying before it needs painting.

Step One: Clean It Properly

Preparation decides whether your finish lasts three years or ten. Paint sticks to clean, sound, dry concrete — not to algae, moss or old sealant.

• Clear the space. Move pots, furniture and the barbecue well out of the way. Lift any loose weeds from the joints between slabs.
• Treat organic growth. Brush off moss with a stiff yard broom, then apply a patio or fungicidal wash to kill the roots. Leave it to work for the time stated on the bottle, usually 24 hours, then rinse thoroughly.
• Wash the surface. A pressure washer on a medium setting lifts years of grime, but keep the lance moving and don't hold it in one spot, or you will etch the concrete and create a rough patch that shows through the paint.
• Degrease. Oil drips and barbecue splashes need a dedicated degreaser, not just water.
• Let it dry completely. This is the step people rush. Give it 48 hours in good weather — longer in cool, damp conditions. Damp concrete traps moisture under the paint, and that moisture will blister the finish within a season.

Repair Cracks and Holes

Once the patio is dry, fill any cracks wider than a couple of millimetres with an exterior-grade patching compound or a stiff mortar mix. Press it in firmly, strike it level with the surrounding slab and let it cure fully before sanding smooth. Fill small pitted areas too, or they will drink paint and leave a flat, dull patch.

Check your drainage. If water pools near a drain or against the house, brush a little mortar into the low spot to restore the fall. Mask off drain covers and the base of any wall with tape and paper before you start painting.

Choosing Masonry Paint That Survives a British Winter

Use paint made for exterior masonry, not interior emulsion and not standard floor paint. Look for two things on the tin: a description such as acrylic masonry paint and wording that mentions exterior use, weather resistance and breathability. Breathable paint lets trapped moisture escape, which matters enormously through freeze-thaw cycles.

• Smooth masonry paint gives a flat, modern finish and is easy to roller. Best for patios in good condition.
• Textured masonry paint hides small imperfections and adds a subtle grip, which is useful on shaded or north-facing patios that stay damp.
• Anti-slip additive is worth considering if your patio slopes or you have young children. Stir it into the final coat.

As a rough guide, a 5 litre tin covers around 20 to 30 square metres per coat. Measure your patio before you buy — a typical 3m x 4m space needs roughly one tin for two coats. Buy a little extra for touch-ups.

Priming and Applying Even Coats

Bare, chalky or previously unpainted concrete benefit from a diluted stabilising primer, which binds dusty surfaces so the topcoat grips. Follow the tin's dilution ratio and allow it to dry fully.

Then work in sections and keep a wet edge so you never see a join line.

• Cut in first. Use a 50mm brush along edges, around drain covers and against walls.
• Roll in one direction. A long-pile roller loads plenty of paint. Work in roughly one-metre squares, rolling in a consistent direction, then lay off lightly to even it out.
• Two thin coats beat one thick coat. Thick paint skins over, traps solvent and wears badly. Allow the stated recoat time, usually four to six hours in warm weather.
• Stir, don't shake. Shaking traps air bubbles that pop and leave pinholes.

Weather, Drying Times and Aftercare

Aim for a dry, settled forecast with temperatures between about 10°C and 25°C. Avoid painting in direct hot sun, as the paint dries too fast to level, and never paint if rain is due within 24 hours. Early autumn and late spring are the sweet spots.

Keep foot traffic off for at least 24 hours and leave furniture off for two or three days — longer in cool conditions. Once cured, sweep regularly rather than pressure washing, and touch in any scuffs each spring. Treated well, a painted concrete patio will carry you comfortably through five to eight British winters.