NBS Source

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

Saint-Gobain Weber Third party certifications:
  • QA Certificate

    QA Certificate

    Certificate type

Fibre-reinforced, rapid drying, self-smoothing, acoustic floor system.

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+44 (0)1525 718877 www.uk.weber


The system is to be covered with 3 mm Thermal Economics IsoRubber Top.

Minimum substrate strength: 1 N/mm².


Fibre-reinforced, rapid drying, self-smoothing, acoustic floor system. Manufactured in accordance with BS EN 13813: 2002. Complies with BS 8204-7. Not for use with underfloor heating.

Can be used to fulfil Robust Details floor solution E-FC-9, comprising a resilient layer directly applied to weberfloor screed.


- Primer/ Bonding coat (weberfloor 4716 primer):

  • Styrene acrylate dispersion which can be diluted with water. Designed for pre-treating all substrates prior to the application of weberfloor products
  • Regulates the porosity of the substrate.
  • Improves the adhesion and flow of flooring products.
  • Reduces the formation of pinholes in the levelling layer.

- Mesh reinforcement (weberfloor 4945 - not for use with underfloor heating):

  • Glass fibre reinforcement net with an alkaline ­resistant impregnation.
  • Specifically for use on weak substrates or in case the screed is laid non­-bonded.
  • Reinforces weberfloor base and renovation screeds in floating floor applications.

- Base screed (weberfloor base rapid 4360):

  • Minimum 40 mm thickness (capable of meeting acoustic requirements).
  • Rapid drying self-smoothing thick base screed.
  • Incorporates Low Dust Technology™, which provides a strong base layer for receiving tiles or a thin topping screed, and reduces the amount of waste and airborne dust produced during application.
  • Can be pump or hand applied.
  • Rapid drying, allowing an early overlay when compared to traditional sand/ cement or concrete screeds.
  • Low alkalinity.
  • Casein-free.
  • For use over precast slab at 150 mm (minimum) with a density of 300 kg/m³ (minimum) (capable of meeting acoustic requirements).

- Damp proofing membrane (weberfloor DPM - for use where required):

  • Two-coat epoxy resin damp proofing system.
  • Easy to apply onto concrete and cement based levelling compounds.
  • Suppresses the passage of moisture up to 98% RH.
  • Reduced project timescale, allows early installation of floor finishes.
  • Resistant to a wide range of chemicals.

- Top layer topping screed (weberfloor smooth rapid 4160):

Used in conjunction with 4360.

  • Requires pre-application of weberfloor 4716 primer.
  • Rapid drying self-smoothing thin topping screed.
  • Can be pump or hand applied.
  • Good spreading and smoothing characteristics.

Weber will only guarantee the products which form the system. Where membranes/ DPM by others are used, these will require a guarantee by the membrane/ DPM manufacturer.

Please ensure movement joints coincide with the building and can be used to assist with sequencing of application.

Preparation/ Recommendations:

  • The substrate should be clean, free from dust, grease and other impurities that might prevent adhesion. All damaged and friable material should be removed. Leaving a good sound, solid substrate, this remedial work should then be a minimum 20 mm deep from the existing datum and 200 mm in length and width. This 200 mm should encapsulate the damaged area by a minimum of 50 mm. Should the damaged area be greater than 200 mm the excavation should always be a minimum of 50 mm past the furthest point.
  • Prior to the final floor finish being applied, please ensure the weberfloor is suitably protected once cured.
  • Reaction to fire clarification has not been determined/ tested and therefore this product is not suitable to be left exposed. For further details, please refer to table ZA.1.1 (page 22) of BS EN 13813 and contact Weber technical team. Prior to installation of Weber floor products, please consult with your local building control authority or equivalent to ensure a reaction to fire classification is not required - especially for onerous areas such as protected shafts, fire exits and fire corridors.
  • In compliance with Scotland Technical Handbook (section 2 – 2.2.6 Combustibility), this product should not be used to a domestic buildings that does exceed 18 m in storey height when installed onto a separating floor, Please refer to the Scotland Technical Handbooks for further information.

Please note that weberfloor fibre 4360 and 4160 should not be painted or used without a floor finish.

Consult manufacturer's literature for specific mixing instructions.

General information






Pr_35_31_06_28 Fibre-reinforced levelling screed mixesPrimary


M10/165 Proprietary fibre reinforced levelling screeds

Product range

Flooring Products

Specification data - Fibre-reinforced levelling screed mixes Enhanced data

Fibre reinforcement

weberfloor 4945 glass fibre mesh.

  • Mesh gauge: 10 x 10 mm.
  • Consumption: Approx. 1.1 m² with overlapping.
  • Colour: White.

Product Reference

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

Primer/ Bonding coat

The substrate should be vacuum cleaned, prepared and primed with weberfloor 4716 primer, according to the manufacturer's instructions (e.g. mixing recommendations). Priming improves the screed’s adhesion to the substrate and prevents the formation of air bubbles and dewatering of the screed. Dry and very porous substrates (cast-in-situ concrete floors) may need to be treated twice. If the screed is applied in more than one layer, each layer must be primed.

weberfloor 4716 primer.

Minimum of two coats.

  • Coverage: 0.2-0.4 kg/m².

Base screed

weberfloor base rapid 4360.

  • Minimum thickness: 40 mm (capable to meeting acoustic requirements); maximum thickness: 80 mm.
  • Water requirement: 4.5 L/ 25 kg (18%).
  • Compressive strength (to BS EN 13813): C30.
  • Flexural strength (to BS EN 13813): F6.
  • Flow rate: 180–210 mm.
  • Material consumption: 1.85 kg/m²/mm.
  • Hardening time (in normal conditions): 1-7 days.
  • Release of corrosive substances (to BS EN 13813): CT.
  • Shrinkage (after 28 days): <0.05%.
  • Applied to precast slab at 150 mm (minimum) with a density of 300 kg/m³ (minimum).

Damp-proofing membrane (DPM)

weberfloor DPM.

For a fully bonded construction.

  • Adhesion to concrete (to BS EN 1542: 1999): 3.9 N/mm².
  • Bond to new concrete: >2.5 N/mm².
  • Average coverage per pack: 7.5 m² (over two coats).
  • Minimum temperature use: 5°C.

Top layer

Domestic and commercial thin coat topping screed, to be applied to a maximum thickness of 30 mm. Consult manufacturer for further details.

weberfloor smooth rapid 4160.

For use prior to the overlay of 3 mm Thermal Economics IsoRubber Top.

Used in conjunction with 4360.

  • Thickness: Minimum: 2 mm; maximum: 30 mm.
  • Water requirement: 5 L/ 25 kg (20%).
  • Compressive strength (to BS EN 13813): C30.
  • Flexural strength (to BS EN 13813): F7.
  • Shrinkage (after 28 days): <0.06%.
  • Flow rate: 240–255 mm.
  • Material consumption: 1.7 kg/m²/mm.
  • Hardening time (in normal conditions): Before foot traffic: 2–4 hours; before 3 mm Thermal Economics IsoRubber Top: 1–7 days (dependent on layer thickness and drying conditions).
  • Release of corrosive substances (to BS EN 13813): CT.
  • Wear resistance: RWFC 550.

Accessories/ Other requirements

Consult manufacturer for details and insert requirements.

Application temperature



Weber Flooring Systems

Weber Flooring Systems

Third party certifications

  • Declaration of Performance (DoP): 180220

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