Coat external walls.

Beyond aesthetics, a professional coating can help address minor structural issues like hairline cracks and prevent penetrating damp. Because these coatings are designed to be breathable, they allow moisture to escape from inside the home while preventing water from entering from the outside.

What Does the Work Involve?

• Surface Preparation: High-pressure cleaning to remove dirt, algae, moss, and loose debris.
• Wall Repairs: Filling cracks, repairing blown render, and treating any existing damp patches or "spalling" brickwork.
• Masking: Protecting windows, doors, gutters, and pathways with heavy-duty tape and plastic sheeting.
• Primer/Bonding Coat: Applying a specialist primer to ensure the top coating adheres perfectly to the substrate.
• Application: Applying the final weather coating, typically via high-pressure spray equipment for an even, textured finish.
• Clean Up: Removing all masking materials and ensuring the site is left tidy.

Typical Costs

Pricing is primarily influenced by the condition of your existing exterior walls; if significant render repair is needed, labour costs will rise. Additionally, the type of coating—such as silicone-based, resin, or cork—will impact the material price point.

Pro Tip: Always ask if the quote includes scaffolding. Some tradespeople provide their own towers, but full scaffolding is often a separate third-party cost.

How Long Does It Take?

• Small Terraced House: 2–3 days.
• Average Semi-Detached: 3–5 days.
• Large Detached Property: 5–8 days.
• Weather Factor: Work cannot be carried out in heavy rain or sub-zero temperatures, which may cause delays.

DIY or Professional?

While basic masonry painting is a common DIY task, applying high-performance external coatings is strictly a professional job. These systems require specialist high-pressure spray equipment and industrial-grade resins that are not available in standard DIY shops.

Furthermore, professional application usually comes with a 10 to 20-year guarantee. Attempting this yourself without the correct prep work often leads to the coating peeling within a few seasons, which is incredibly difficult and expensive to rectify.

Choosing the Right Tradesperson

• Check Portfolios: Look for "before and after" photos of local projects completed at least two years ago to see how they have weathered.
• Verify Guarantees: Ensure the guarantee is insurance-backed, so you are protected even if the company stops trading.
• Ask about Breathability: Confirm the product has a high "SD value" to ensure it doesn't trap moisture in your walls.
• Questions to ask: "Do you use a primer or a bag-rubbing technique?", "Is the coating spray or roller applied?", and "How do you handle cracks in the render?"

UK Regulations

• Permitted Development: Most wall coatings fall under permitted development and don't require planning permission unless you live in a Listed Building or Conservation Area.
• Building Regs: If you are renovating more than 25% of a wall's surface, you may technically need to improve the thermal insulation of that wall to meet current standards.
• Health and Safety: Contractors must comply with "Working at Height" regulations, often necessitating professional scaffolding over ladders.

Common Problems

• Trapped Moisture: Applying a non-breathable coating over damp walls can cause the coating to bubble and the interior walls to develop mould.
• Poor Preparation: If algae and dirt aren't fully removed, the coating will fail to bond and eventually peel away in sheets.
• Thin Application: Some "cowboy" traders water down the product or only apply one coat, significantly reducing the lifespan of the protection.
• Overspray: Inexperienced sprayers may leave residue on your driveway, car, or your neighbour's property if masking isn't meticulous.

Frequently Asked Questions