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ARDEX A 38 is a special cement for producing a rapid setting, hardening and drying floor screed for internal or external use, including swimming pools, allowing ceramic tiles or stone to be fixed after only four hours, even on unbonded and floating screeds. ARDEX A 38 can be used to produce a bonded screed, an unbonded floor screed laid onto a membrane, or a floating floor screed laid onto a compressive quilt/ insulating material.


  • Rapid hardening – walkable in three hours.
  • Receives ceramic and natural stone tiles directly after only four hours for bonded, unbonded and floating screeds.
  • Install resilient, wood finishes and vinyl floor coverings after 48 hours.
  • After only one day the compressive and tensile bending strengths of ARDEX A 38 exceeds the acceptable minimum attained by an ordinary cement screed after 28 days.
  • Can be used with underfloor heating systems.
  • Can be pumped for fast application.

Related literature

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Standard product features

Compressive strength:

  • After 1 day: 25.0 N/mm².
  • After 7 days: 40.0 N/mm².
  • After 28 days: 45.0 N/mm².

Tensile bending strength:

  • After 1 day: 4.0 N/mm².
  • After 7 days: 4.5 N/mm².
  • After 28 days: 5.5 N/mm².



ARDEX A 38 should be applied at the following thicknesses for normal cement/ sand screeds:

  • Minimum 15 mm (design thickness up to 40 mm) for bonded screeds.
  • Minimum 50 mm for unbonded screeds.
  • Minimum 75 mm for floating screeds (65 mm in lightly loaded (domestic) locations).

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-55-10/380 Quick drying levelling screed mix

Product specification

An important note about specifying





+44 (0)1440 714939

Product reference

ARDEX A 38 Ultra Rapid Drying Cement for Internal & External Screeds

Manufacturer details

Homefield Road,
Suffolk, CB9 8QP
Tel +44 (0)1440 714939
Fax +44 (0)1440 716667
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