2.4m Fibre Cement Backer Board for Construction, Exterior Grade

Fibre cement backer boards have excellent water-resistant properties, meaning that these boards last much longer than ply or plaster alternatives. Fibre cement boards give a suitable, even surface for tiling onto and can be used for covering up damp-prone areas or uneven walls/floors.

When working with fibre cement boards, it is important to wear safety gloves when cutting, moving, and handling the boards.

Please note: due to the fibre cement material, it is advised that when cutting boards, a dust mask is worn. Remove any residue or dust with a dampened cloth to avoid particles from entering the air. 6mm and 9mm boards can be cut to size using a scoring knife or blade and a straight edge. For 12mm and 18mm boards, we recommend cutting the thicker fibre cement backer boards on a bench using a circular saw that has been fixed with a vacuum extractor and filter. This will make for a clean, straight line whilst reducing the amount of dust in the surrounding air.

As a multi-use product, fibre cement backer boards can be fitted under tiling, onto walls, as replacement floorboards, fitted directly onto cement floors, as ceiling boards, or as a fire surround for fireplaces.

Fibre cement backer boards are multi‑use and can be installed in a wide range of applications, depending on board thickness. Please note that all boards used in flooring installations must be laid in a brick‑bond (staggered) pattern to prevent four corners meeting at one point.

6mm boards are commonly used on concrete floors, as their slim profile won’t raise floor levels and helps deliver a squeak‑free finish. Fix 6mm boards directly to the concrete subfloor using a flexible adhesive or polymer‑enriched thin‑set mortar. Allow at least 24 hours to set before screwing into place. Seal joints by applying thin‑set mortar over mesh tape using a smooth putty knife.

9mm and 12mm boards are recommended for wall installations, with thickness chosen based on the application. For stud walls or high‑traffic areas such as corridors, 12mm boards are preferred due to their increased strength and improved sound‑reducing properties. Secure them using screws and washers positioned at least 20mm from the board edges. For solid walls, 9mm boards are recommended and can be fixed using a flexible rapid‑set adhesive, then mechanically secured once set.

18mm fibre cement boards are best suited to new‑build floors and underfloor heating systems. Their increased thickness provides improved strength, sound insulation, and thermal performance. They can be installed directly onto joists as floorboards and offer greater stability than timber‑based alternatives, with minimal risk of movement.

Fibre cement backer boards are a multi-use product and can be installed on walls, ceilings, and floors, including under tiling. They can also be used around fireplaces (as a fire surround/backer) and in other areas where a stable, moisture-resistant board is needed.

Fibre cement backer boards are manufactured from a combination of cellulose fibres and cement mix, making them a non-combustible A1 fire-resistant material and ideal for use around fireplaces.

For a detailed report of our backer board fire resistance, please take a look at our accreditation page here.