15mm x 120mm x 3900mm Treated Shiplap Cladding (Tanalised Softwood) is an exterior-grade timber cladding profile designed to provide a weather-tight, protective, and decorative outer skin for outdoor wooden structures.

Primary Uses & Key Features

• Garden Buildings & Sheds: The standard specification for constructing or re-cladding garden sheds, summerhouses, workshops, and log stores.

• Fencing & Screen Panels: Ideal for building continuous, privacy-focused garden fencing, decorative boundary walls, and bin stores.

• Tanalised Pressure Treatment: Vacuum-treated with wood preservatives (Tanalith E) to protect the softwood against fungal decay, wood-rotting fungi, and insect attack, ensuring long outdoor service life.

• Superior Water Run-Off Profile: Features a scalloped rebate and overlap edge that draws rainwater away from the joints, preventing water pooling and moisture penetration inside the structure.

• Long 3.9m Length: The 3900mm length minimizes horizontal end-to-end joints, making it ideal for wrapping larger garden structures cleanly.

 

Available for collection from our Rugby branch or local delivery using our own fleet.

Delivery is kerbside and the final offloading position is always subject to safe access and the driver’s discretion.

Please tell us before delivery about:

• Narrow roads or restricted entrances
• Parked vehicles or limited turning space
• Overhead cables, trees or other obstructions
• Soft, sloping or unsuitable ground
• Any other access concerns

Enter your postcode on the product page to check your delivery area. We’ll confirm the delivery date after your order is placed.

What is the actual face coverage width of 120mm shiplap cladding?

The nominal width is 120mm, but after accounting for the overlapping rebate profile, the visible surface coverage (face width) is typically around 108mm to 110mm. You must use this reduced coverage width when calculating board quantities for a wall area.

Which direction should Tanalised shiplap boards be installed?

Shiplap is designed for horizontal installation. Always install the boards with the upper profile lip pointing upwards and the overlapping rebate facing downwards. This orientation uses gravity to shed rainwater away from the joint.

Do you need to treat cut ends during installation?

Yes. Cross-cutting boards exposes the untreated core timber. You must coat all freshly cut ends, drill holes, and notches with a brush-applied end-grain preservative to maintain protection against rot and insect attack.

What fixings should be used to attach shiplap cladding?

Use stainless steel or hot-dipped galvanised ring-shank nails or screws. Standard bright steel fixings will react with the moisture and Tanalith treatment chemicals, causing rust bleed and unsightly black streaking down the timber face.

Can you paint or stain Tanalised shiplap immediately after purchase?

Freshly pressure-treated timber often arrives slightly damp from the treatment process. Allow the wood to dry out thoroughly on-site for a few weeks until the greenish tint fades before applying exterior wood stains, paints, or oils.