ARDEX Rapidlay Membrane is a specially coated and patterned fibreglass reinforced sheet underlay designed to overcome the problems sometimes encountered in laying floor coverings, particularly sheet vinyl flooring, over new or old sub-floors in domestic and light commercial areas.


  • Screed or concrete substrates where construction moisture has not fully dried out (5% moisture content, 92% RH maximum).
  • Anhydrite screeds with a maximum of 2% moisture content (carbide method).
  • Areas where sub-floors have been exposed to water spillage.
  • Old sub-floors which do not contain a fully functioning damp proof membrane.
  • Over old, soundly fixed flooring when a temporary covering is to be applied (without adhesive).
  • Suitable for use on heated concrete or cement/ sand screeds up to 27ºC maximum temperature.

Rapidlay Membrane should not be used in:

  • Areas that are subjected to heavy wheeled traffic such as forklift or pallet trucks, chair castors etc.
  • On timber bases that are not adequately ventilated.
  • On sub-floors that are subject to hydrostatic pressure.
  • On sub-floors which contain an effective damp proof membrane, but exceed a relative humidity of 97% and on sub-floors with no damp proof membrane and a relative humidity above 92%.
  • On magnesite or composite floors.
  • Biologically sensitive areas, or where floorings must be fully adhered, such as prisons.


  • It provides a continuous base which is stable and resistant to damp.
  • It cuts down laying time as there is no need to wait for the normal subfloor drying times.
  • It is dimensionally stable.
  • Quick installation can be achieved as it is a sheet system.
  • Allows for a new temporary floor to be laid over an existing floor (without potential adhesive damage on uplifting).
  • Low VOC and solvent free product.

General information


Provides a stable, moisture resistant barrier substrate; Perfect for use over damp and contaminated subfloors; Reduces or eliminates the need for mechanical preparation,


1.4 x 1450 x 25000 mm

Uniclass 2015

Pr_35_31_06_28 Fibre-reinforced levelling screed mixesPrimary


M10/280 Unbonded construction

M10/290 Floating construction

M10/40 Floating construction

M40/451 Preparing concrete bases for unbonded bedding

Product range


Specification data - Fibre-reinforced levelling screed mixes

Product Reference

ARDEX Rapidlay Membrane

Standard product features

Packaging and coverage:

  • Width: 1.45 m.
  • Length: 25 m.
  • Coverage (per roll): 36.25 m².
  • Thickness: 1.4 mm.

Digital objects

Platform Compatible Version Certified to

Revit 2016




Download now from NBS National BIM Library


ARDEX Tiling Guide

ARDEX Tiling Guide

Third party certifications

  • Registration Number - FM 1207

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ARDEX FA 20 Levelling and Smoothing Compound for Timber Floors