Concrete exterior paint
— elastic coating with liquid rubber

Pressure washer (min. 150 bar) — remove dirt, algae, loose particles and salt efflorescence. Close cracks > 1 mm with repair mortar, fill spalled areas and let cure for 7 days. Remove form oil and laitance mechanically or dissolve with concrete cleaner.

Residual moisture must be below 4 % — for fresh concrete wait at least 28 days of curing.

Pro tip: Spot laitance (shiny surface layer) with the water-drop test — if water beads up, the surface needs sanding or concrete cleaner treatment.

On strongly absorbent concrete (fresh exposed concrete, old plinths, lime sandstone) apply a hydrophobising deep primer. Reduces first-coat consumption by up to 30 % and significantly improves coating anchorage. Let dry for 12 h before further work.

On sound, closed old paint, primer can be skipped — proceed directly to Step 3.

Pro tip: Don't apply deep primer thickly — a thin, absorbed coat is enough and prevents glossy spots that would weaken adhesion.

Dilute with up to 5 % water (airless sprayer up to 10 %). Apply with lambswool roller or wide brush. Diluted, the paint penetrates deep into the pores and anchors. Consumption on strongly absorbent concrete 200–250 g/m², on normal exposed concrete 100–150 g/m². Full-surface in one pass, no visible joins.

Particularly careful at plinth edges and water-run-off points — these are exposed to splash water.

Pro tip: On large areas work in strips of about 1 metre wide — prevents visible join lines between separate passes.

The first coat must be fully dry through. In cool weather or high humidity wait longer — up to 12 h. Test: the coat must no longer be tacky to finger pressure and leave no impressions.

Protect the concrete surface from direct sun and rain during drying — direct sun risks streaking from drying too fast on the surface.

Pro tip: Work mornings on the shaded side, afternoons on the sunny side — follow the sun and use the best temperatures.

Apply undiluted, cross to the first coat. Consumption 150–200 g/m². Rain-resistant after 6 h (manufacturer specification), fully load-bearing after 28 days. For plinths or retaining walls in the splash zone a third coat is recommended — extends service life by years.

At splash-water edges (lower 30 cm) apply the second coat slightly more generously for extra protection.

Pro tip: Judge the final colour only after full curing (28 days) — fresh coating looks slightly milky but clears up completely.