NBS Source
weberfloor flex


  • The product can be applied onto difficult surfaces including existing tiles and paints, and over under tile warming or under floor heating systems.
  • Not recommended for industrial areas, wearing surfaces, use externally or wet or permanently damp conditions.


weberfloor flex is a high-performance, fibre-modified, cement-based, self-smoothing, rapid-setting floor screed with low dust technology. The product is formulated from special cements, aggregates and chemical admixtures. weberfloor flex is for use in residential and commercial areas, correcting surface irregularities on difficult surfaces, including wood, in interior situations, ideal for rapid completion of tiling projects.

Features and benefit:

  • Weber Low Dust TechnologyTM improves comfort of applicators.
  • Excellent levelling properties.
  • Can be built up to 50 mm.
  • Rapid setting (tile on after 1 – 2 hours).
  • Improved bond to difficult substrates.
  • Flexibility to absorb limited movement, e.g. under-floor heating and wood.
  • Fibre-modified for increased resilience.

Technical characteristics:

  • Compressive strength (to BS EN 13813): C25.
  • Flexural strength F5.
  • Weight: 25kg.
  • Coverage: 1.7 m² per 25 kg bag, when applied at 10 mm thickness.
  • Application Temperature:- +5°C to +30°C.


  • Substrate to be completely dry, hard, rigid and clean.
  • Remove any traces of paint, plaster, laitance, old adhesive or other unsound materials.
  • Thoroughly remove all traces of dust by vacuuming or sweeping.
  • Switch off any under-floor heating systems at least 24 hours before application.
  • Localized holes up to 50 mm deep can be filled with weberfloor flex and allowed to dry.
  • It is recommended that all porous surfaces are primed with weber PR360.
  • For anhydrite screeds, it is essential that the screed surface is primed with weber PR360. Allow to dry for 1–4 hours.
  • Impervious surfaces to be primed with weber PR360 and allowed to dry for 1–3 hours.
  • Must be 10°C.

General information




Pr_35_31_06_28 Fibre-reinforced levelling screed mixesPrimary
Ss_30_42_15_10 Bonded or partially bonded cementitious levelling screed systems


M40/110 Tiling to

M40/120 Mosaic to

M40/10 Natural stone covering to

M40/115 Natural stone covering to

M40/5 Tiling to

Product range

Tile Fixing Products

Specification data - Fibre-reinforced levelling screed mixes Enhanced data

Product Reference

weberfloor flex


1.5 m² per 25 kg bag, when applied at 10 mm thickness.

Application temperature

+10°C to +30°C.


1 N/mm².


5 litres/ 25kg (20%).


C 25.

Flexural strength

F 5.


Consumption: 1.7kg/ m²/ mm.

Pot life

20 min (after adding water).

Drying time

1–2 hours. (24 hours at 5 mm thick before covering).


  • Minimum Thickness Under Tile Warming >3 mm over the heating wires
  • Minimum Thickness Underfloor Heating >15 mm over the heating pipes
  • Minimum Thickness Floating Floor 25 mm (with weberfloor 4945 fibre mesh)
  • Minimum Thickness Over Wood 10 mm
  • Minimum Thickness Over Slip Membrane Solid Substrate 20 mm.

5–50 mm.


Smooth, finished with various floor coverings.

Digital objects

Platform Compatible Version Certified to




Download now from NBS National BIM Library

Similar products from Saint-Gobain Weber

WeberSpec Acoustic Above Floor - Precast Slab at 150 mm (minimum) with a density of 300 kg/m³ (minimum)

WeberSpec Acoustic Below Floor

WeberSpec Industry Rapid Floor

WeberSpec Smooth Floor

WeberSpec Smooth Rapid Floor

WeberSpec Smooth Thick Floor

WeberSpec Smooth Timber Floor

WeberSpec Smooth Timber Rapid Floor