Composite Cladding Corner Trim Installation: Step-by-Step Guide

Corner trims are the finishing touch that completes any cladding installation, giving façades clean edges and a professional appearance. Properly fitted corner trims not only enhance aesthetics but also protect exposed board edges from moisture ingress and impact.

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Thu, 28 Jul 2026

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This composite cladding corner trim installation guide explains how to fit corner profiles, with best practices for cladding systems.

Why Corner Trims Are Important

Corner trims are more than decorative, they contribute to the long-term performance of your cladding system.

Key benefits include:

  • Edge protection: Helps divert rainwater and prevent ingress behind the façade.

  • Aesthetic continuity: Provides a neat, professional finish on corners.

  • Movement allowance: Hides expansion gaps between boards.

Without trims, exposed board edges can absorb moisture, collect debris and detract from the overall appearance of the installation.

How to Install Composite Cladding Corner Trim

Corner Trim can be used on its own or with Fascia Boards to cover cladding board edges and exposed substructure at corners, doors and window frames.

Step 1

Measure the required amount of Hyperion Corner Trim and cut down to size.

Step 2

If corner trim ends are being placed next to each other at wall edges mitre down at 45 degrees.

Step 3

Place over the corner to cover, pre-drill and countersink through the trim.

Step 4

Screw into place with countersunk A2/A4 Stainless Steel screws.

  • If you are concerned about visible screws, coloured screws and screw caps are available from general builders merchants.

Step 5

Corner Trim can be combined with fascia boards to cover deeper window and door frames

Common Mistakes to Avoid

  • Over-tightening screws (causes warping or cracking).

  • Cutting trims too short or unevenly.

  • Forgetting to leave expansion gaps behind boards.

A Perfectly Finished, Rainscreen Façade

Installing cladding corner trims is the finishing stage that transforms a good installation into a professional one. Properly fitted trims enhance aesthetics, protect edges and ensure long-term durability.

By following these best practices, you’ll achieve a clean finish that complements any building style.

EnviroBuild supplies a complete range of composite cladding systems and trims, designed for effortless installation, exceptional durability and contemporary style.