A triangular piece of wood called a "fillet timber" is used to improve the look and performance of concrete buildings. Its primary function is to provide formed corners of concrete slabs, columns, finished upstands, and hobs a clean, chamfered edge. This chamfered edge minimizes sharp edges and potential risks while also adding a decorative touch to the concrete structure and creating a smooth transition between surfaces.

In addition to its use on corners, the fillet timber is also utilized to create drip grooves in exposed slab soffits. These grooves help to channel water away from the concrete surface, preventing water buildup and potential damage over time. By incorporating drip grooves, the fillet timber contributes to the overall durability and longevity of the concrete structure, reducing the risk of water-related issues such as erosion or cracking.

Constructed from high-quality timber, the fillet timber is durable and easy to work with, allowing for seamless installation and integration into concrete construction projects. Its versatile design and practical functionality make it an essential component for achieving clean and professional-looking concrete finishes while also improving the structural integrity and weather resistance of the concrete elements.