Description
The 6mm NoMorePly PrePrimed Fibre Cement Tile Backer Overboard 1200 x 600mm (4′ x 2′) does one job exceptionally well: it stiffens a timber floor before tiling, so the tiles and grout don’t crack from footfall. It is supplied by NoMorePly, a UK brand by STS Ltd, and made from Portland cement, organic cellulose fibres, sand and water.
The clever part is the thickness. According to NoMorePly, a 6mm overboard provides similar strength and rigidity to 15 to 18mm plywood while adding barely any height to the floor. That means no awkward step between rooms when you tile a bathroom or kitchen next to carpeted or wood-floored areas. It also means you can lay it over existing floorboards quickly without rebuilding levels.
Why the PrePrimed version
The board comes ready-primed on one side. You skip the priming stage, save time on site, and avoid the dust. The primed face goes up, and you tile straight onto it. Each board is 1200 x 600mm and weighs just 6.25kg, so a single person can carry and lay them comfortably. The compact size also makes them easier to manoeuvre into tight spaces.
Fire and water performance
The board is Euroclass A1 non-combustible under EN ISO 1182 and EN ISO 1716, the top fire rating possible. It’s also fully water-resistant: density of 1.28 g/cm³, linear moisture variation of just 0.16%, and it passes the complete BS EN 12467:2016+A1:2016 durability suite (freeze-thaw, soak-dry, warm water, heat-rain). Unlike plywood, it won’t weaken, swell or rot when wet, which is exactly why professionals choose it for bathrooms and wetrooms over timber-based substrates. Bending strength stays strong even when soaked: 17.56 MPa dry and 12.97 MPa saturated.
The board also resists mould and termites, works well with both electric and water underfloor heating systems, and is suitable for internal and external use. The board takes tiles up to 60kg/m², which covers virtually all standard ceramic and porcelain floor tiles, including large-format ones.
Applications
- Strengthening timber floors before tiling in bathrooms, wetrooms, cloakrooms and kitchens
- Tile substrate in saunas, steam rooms and hallways
- Underfloor heating systems (electric or water)
- Outdoor tiled areas
- Overboarding stud partition walls (with full edge and centre support)
The board is not designed to be fixed directly to joists.
When installed correctly using the NoMorePly fixing system (Mega Strength PU adhesive and 25mm NoMorePly fibre cement screws), the board is covered by a manufacturer’s lifetime guarantee, a unique offer in the fibre cement category.
