How to Paint Exterior Masonry for Lasting Protection
Protect and refresh outside walls with a breathable finish that stands up to British weather.
Painted masonry does more than smarten the look of a property; a good coating sheds rain, resists frost and helps keep damp at bay. Because the walls face the full force of the weather, both the preparation and the choice of a breathable paint are critical.
Plan the work for a spell of dry, mild weather, as masonry paint needs stable conditions to cure properly. Never paint in direct hot sun, drizzle or when frost is forecast overnight.
What you will need
- Stiff brush and bucket
- Stabilising primer
- Masonry filler
- Fungicidal wash
- Long-pile masonry roller
- Large masonry brush
- Breathable exterior masonry paint
Inspect and clean the wall
Check the whole elevation for cracks, loose render and signs of damp before starting. Brush off loose material, dirt and cobwebs, then treat any green or black growth with a fungicidal wash. Allow the treated areas to dry for the time stated.
Repair defects
Rake out and fill cracks with an exterior masonry filler, and make good any blown or hollow render. Larger structural issues should be assessed before any painting begins. Let all repairs cure fully so they do not shrink back later.
Stabilise powdery surfaces
Older or chalky masonry should be sealed with a stabilising primer so the topcoat bonds rather than lifting. Apply it generously to porous areas and allow it to soak in and dry. This step dramatically improves adhesion and coverage.
Cut in around features
Using a large masonry brush, paint carefully around window frames, downpipes, air bricks and the edges of the wall. Keep air bricks and vents clear so the wall can breathe. Protect paths and plants below with sheeting.
Apply the first coat
Work the paint well into the texture with a long-pile roller, loading generously and spreading evenly. On heavily textured surfaces a brush worked into the hollows gives better coverage. Maintain a wet edge across each section to avoid banding.
Apply the second coat
Once the first coat has dried thoroughly, apply a full second coat to build weather resistance and even colour. Two coats are essential outdoors; one rarely gives lasting protection. Follow the recoat time on the tin, which is longer in cool or humid conditions.
Clean up and inspect
Remove sheeting and check the finish in good light for any missed patches or thin areas, touching these in while the paint is fresh. Clean tools promptly before the paint sets. Keep an eye on the wall over the first weeks of weathering for any defects to address.