White UPVC 3m x 9mm Capping Board – Depth Options: 100mm to 400mm

White UPVC Capping Board – 3m Long, 9mm Thick (100–400mm Depth Options)
Transform your window sills effortlessly with our premium White UPVC Capping Boards, engineered for high performance, durability, and a sleek finish. These 3-metre long, 9mm thick boards are specifically designed to cover and upgrade damaged or outdated timber or MDF sills without the need for removal or costly renovations.

Perfect for sill renovations in residential and commercial properties, this plastic capping board is crafted from exterior-grade UPVC that is fully waterproof, UV-stable, and resistant to warping, cracking, or discolouration over time. Whether you’re completing a DIY project or a professional installation, our white capping boards offer a low-maintenance solution that enhances any interior.

Each board comes in a full 3-metre length for extended coverage, with a robust 9mm thickness to provide extra rigidity and impact resistance. With depth options from 100mm to 400mm, it’s easy to find the ideal fit for any sill – from narrow reveals to wide modern window boards.

🔧 Key Product Benefits

• Extra-long 3m length – fewer joints, perfect for wide or continuous sills

• Rigid 9mm UPVC – more durable than 5mm alternatives

• Fully waterproof – ideal for bathrooms, kitchens, conservatories, and utility rooms

• UV-resistant finish – colourfast and fade-resistant for long-lasting appearance

• Quick installation – cut to size and fix with adhesive or screws

• No maintenance required – wipe-clean surface, no painting or sanding needed

• Depths available: 100mm, 150mm, 175mm, 200mm, 225mm, 250mm, 300mm, 400mm

• Optional accessories: end caps, corners, connectors, and adhesives sold separately

🏠 Ideal Applications

• Refurbishing internal window sills in homes, flats or offices

• Landlord renovations or fast improvements before letting/sale

• Protecting wooden sills from water ingress

• Sealing cold drafts around old sill areas

• Fast aesthetic upgrades before inspections or valuations

📐 Technical Specifications

🛠️ Installation Guide

1. Clean existing sill surface to remove dust and grease

2. Measure and cut board to size using a fine-tooth saw

3. Dry-fit to confirm positioning

4. Apply strong grab adhesive (e.g. CT1, No More Nails)

5. Press firmly into place and hold for 60 seconds

6. Optional: seal around edges with white silicone for a seamless look

7. For joins over 3m, use a butt joint or matching connector trim

✅ Why Choose Windows4You?

We are a trusted UK-based supplier of UPVC window trims, capping boards, fascia and soffit systems, serving thousands of satisfied customers. Our stock is sourced directly from reputable manufacturers, ensuring quality, value, and fast availability.

Windows4You – Newcastle-under-Lyme
Your partner in premium UPVC building products across the UK.

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