Corner Trim Profile

Corner trims for timber cladding

Corner trims finish the external and internal corners of a cladded wall. Without a trim, the boards meet at an exposed end-grain mitre or butt joint that is vulnerable to water and can look untidy. A trim protects those edges, hides the join and gives the building a deliberate, finished appearance.

Types of corner

• External corner trims are often L-shaped or square, wrapping the outside corner of the wall.
• Internal corner trims are usually a small square or quadrant section that covers the junction of two walls.
• Start and finish trims neaten the edges beside windows, doors and soffits.

Matching your cladding

Choose a trim in the same timber as your boards so the colour and ageing match. We stock trims to suit larch, western red cedar and thermowood. See the full external timber cladding range to select compatible profiles and thicknesses.

Fitting

Fix the trim to the corner batten or frame with stainless nails or screws, then bring the boards up to it, leaving a small gap for movement. Seal exposed end grain with a suitable oil or end-grain treatment. Make sure the cavity behind remains ventilated.

How much to order

Measure the vertical height of each corner, add them together, and include an extra 10% for cutting. Trims are commonly supplied in standard lengths, so check how many lengths you need per corner to avoid joins. For other detailing, read the timber cladding guide or ask for a made-to-measure option via bespoke cladding.