What goes with this?
Accessories and essentials for this job — add what you need.
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OX Trade Notched Stainless Steel Trowels
Notched trowel for spreading adhesive — pick the notch size for your tile
£11.99inc. VAT
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Larsen Acrylic Pink Primer 1L & 5L, Ready-to-Use Tile Primer
Larsen’s own primer — check suitability for your substrate
From £11.99inc. VAT
Description
Larsen FiberFlex Rapid Set+ (also written Fibreflex) is a fully flexible, S1-rated, fast-setting, cement-based tile adhesive classified C2 FS1, for interior and external floor and wall tiling. It is the fast-track option in the FiberFlex Set+ range, with grouting possible after 3 hours. This listing is the grey version in a 20kg bag.
Key properties
- Classification: C2 FS1 to BS EN 12004 (flexible, rapid setting)
- Suited to most tile types, and recommended for glass mosaic, porcelain, natural stone and large-format tiles
- Recommended for demanding substrates including heated screeds, over-boarded timber and swimming pools
- Suitable for underfloor heating
- Interior and exterior use
- Bed depth 3–12mm, up to 20mm in small isolated areas
- Tensile adhesion strength 1 MPa or more under all test conditions; slip 0.5mm or less; transverse deformation 2.5mm or more and 5mm or less
- Application temperature +5°C to +30°C
- Colour: grey; pack size: 20kg bag; shelf life 6 months unopened
Coverage
Approximately 4 kg/m² at a 3mm bed. Mix 20kg of powder with approximately 4.5 litres of clean water.
Working and setting times
- Pot life: approximately 45 minutes at 20°C
- Grout after 3 hours
- Light foot traffic after 3 hours
- Full traffic after 3 hours
Times are at 20°C and vary with site conditions. With a pot life of 45 minutes, mix in batches you can use promptly. Do not remix or add water once the mix has begun to stiffen.
Application
Mix with a forced action mixer or slow speed drill and paddle to a slump-free mortar. Apply by solid bed on wet areas, all exterior tiling and all floor tiling, and use a notched trowel on dry wall areas. For large-format tiles, also skim the back of the tile with a thin layer of adhesive. Dot and dab fixing is not suitable. Prime where required with Larsen Acrylic Primer: diluted 1:1 on porous substrates, neat on impervious ones.
On underfloor heating, new systems must have been trialled at high temperature for at least 48 hours beforehand, with the heating off for at least 48 hours before tiling and not switched on until at least 7 days after. Bring it up from the lowest setting by no more than 5°C per 24 hours. Plywood and other wood-based boards should not be tiled directly: use an uncoupling membrane, reinforced tanking system or tile backer board. Do not fix tiles to wooden substrates externally or in wet areas, and do not use below 5°C.

