Exterior walls in the UK are susceptible to dampness and moisture damage due to the cool, wet climate. Using waterproofing paint on outside walls can help protect your home from costly repairs.
When searching for the best damp-proof paint for exterior brick, concrete or rendered walls, there are a few key factors to consider.
Also read; House rendering in London
This guide will walk you through the types of waterproof masonry paints available in the UK and what to look for when selecting the right product for your specific project.
Read on to learn how to effectively waterproof exterior walls and prolong the life of your home’s facade.
Also read; Exterior House Painting London
Assessing Your Exterior Walls
Before choosing a waterproofing paint, inspect your exterior walls to identify any existing problems.
Look for areas of efflorescence, which is a white powdery deposit indicating moisture is present. Also check for crumbling bricks or patches of mould, algae or discoloured rendering which suggest dampness issues.
Determining the wall material – whether brick, concrete, rendered, pebbledash or wood – will also help guide your paint selection. Ensure surfaces are in good condition without major cracks or damage. Any necessary repairs should be completed prior to waterproofing paint application.
Choosing a Waterproofing Paint Type
There are a few main types of masonry paint formulated to waterproof exterior walls in the wet UK climate:
Silicone waterproof coatings penetrate porous surfaces and contain silicone to repel water. Silicones are durable and breathable.
Acrylic waterproof paint: acrylic latex paints form a water-resistant barrier. They come in a range of sheens, from matt to satin.
Cement-based waterproofers: These coatings contain Portland cement and bind to surfaces to seal out moisture. Often used on concrete and stucco
Epoxy masonry paints Two-part epoxy paints offer heavy-duty water protection. They form a plastic-like coating once cured.
Lime-wash: Traditional limewash allows walls to breathe while repelling some moisture. Environmentally friendly option.
Consider your walls’ porosity, texture, and condition when choosing the best waterproofing paint formulation. Silicones and acrylics work well for brick, rendered walls and pebbledash. Concrete may require a cement-based or epoxy coating. Limewash suits textured stone walls.
Key Features to Look For
When comparing exterior masonry paints, keep these key features in mind:
Breathability – The coating should allow for some vapour transmission so walls can breathe. This prevents trapped moisture.
Covering power – A high volume of solids to fully coat textured or porous surfaces. At least 10 sq metres per litre.
Durability – Long-lasting protection from weathering. Look for 5-20 years coverage.
Flexibility – Ability to bridge cracks and move with the wall over time. Especially important on older homes.
Masonry adhesion – Bonds well to exterior surfaces like brick, concrete, stucco and stone.
Tintable – Can be tinted to match existing wall color if desired.
Top UK Brands for Waterproofing Paint
Some well-known paint brands in the UK offer quality waterproofing exterior paints:
Dulux Weathershield – Silicone masonry paint provides long-lasting weatherproof protection. Available in a full range of colours.
Johnstone’s – Combines acrylic and silicone for multi-surface waterproofing. Trade grade products.
Sandtex – Offers breathable textured masonry paints and smooth coatings. 10-year guarantee against flaking/peeling.
Craig & Rose – VOC-free mineral silicate masonry paint naturally resists water. Environmentally friendly.
Wethertex – Specialist exterior coatings like silicone, acrylic, lime-wash and mineral paints.
Stormdry – Professional durable masonry coatings for extreme UK weather protection.
Consulting manufacturer specifications can help determine the right product for your particular exterior surface and needs. Consider purchasing a few tester pots to trial before committing to full tins.
Preparing Exterior Walls
Proper surface prep is crucial prior to applying your chosen waterproofing paint. Here are a few tips:
➜ Clean walls thoroughly, removing any dirt, grease, or getting rid of existing flaking paint. Use pressurised water if needed.
➜ Repair cracks, damaged bricks or rendering. Fill any gaps or holes.
➜ Remove any moss, mould or algae with fungicidal wash. Apply herbicide to kill roots.
➜ Allow walls to fully dry before painting. Do not apply if rain is expected in 24 hours.
➜ On powdery or unstable surfaces, apply masonry stabilising solution.
➜ Spot prime with diluted waterproofer paint on any patches or repairs.
➜ Follow manufacturer advice on thinning or mixing two-part epoxy coatings.
Applying Waterproofing Paint
When ready to start painting, follow these tips:
➜ Use manufacturer recommended tools – usually brush, roller or airless sprayer.
➜ Work in sections starting at the highest point on walls to avoid drips.
➜ Apply liberally working paint into the masonry for maximum adhesion and protection.
➜ Allow proper drying time between coats, usually 6-24 hours depending on conditions.
➜ Apply minimum two coats for proper coverage, and three on porous or textured surfaces.
➜ Follow all safety precautions like masks and protective eyewear when spraying.
➜ Avoid application in wet, cold or excessively hot conditions.
➜ Check coating is fully cured before exposing to weathering.
Regular maintenance will maximize your exterior paint’s waterproofing performance and longevity:
- Inspect walls annually – look for any cracks or damage needing touch up repairs.
- Clean walls every 2-3 years, removing grime and mildew. Recoat if flaking.
- Prune back vegetation contacting walls by at least 3 feet.
- Reapply waterproofing paint every 5-10 years or according to manufacturer.
Choosing the right waterproofing paint and properly prepping your exterior walls provides long-lasting protection, improves insulation and prevents costly wall repairs.
Consult paint specialists to ensure you select an optimal product to suit your wall type and maximize durability in the UK climate. With proper application and maintenance, you can keep exterior walls looking great for years.