Underfloor Heating Screeds

Interior Flow™ – Free Flowing Screed

Underfloor Heating Screed Specialists

Adapting to technological change within our business is a priority. Our calcium sulphate screeds or flowing screeds are becoming more common place. Particularly suited to underfloor heating systems our flowing screed systems provide significant benefits over traditional sand:cement screeds.




Features & Benefits of Flowing Screed

Ready to use, our flowing screeds offer many advantages over traditional screeds.

Speed of application
Easily conforms to Class SR2 surface regularity
Accuracy of placement and finishing
Reduced thicknesses
High strength
Elimination or substantial reduction in movement joints
Much improved thermal conductivity through the screed (Underfloor Heating Systems)
Compatible with both electric and water underfloor heating systems
Speed of application – up to 2000m2 per day
Reduced cost
Elimination of a requirement for latex levelling screed
Introduction of anhydrite compatible tile adhesives
Protein free – Suitable for hospitals, floor preparation areas etc
High impact resistance, readily achieving the requirement of Category A
Excellent volume stability, no curling or lifting
Freedom from the need to use reinforcement below ceramic finishes

Technical Data

  • Appearance/Colour: Off-white fluid mortar
  • Water demand: 13-18 % b.w
  • pH: >10
  • Wet Density: 2200 kg/m3
  • Dry Density: 2000 kg/m3

Typical Screed Properties:

  • Compressive Strength: C30 N/mm2
  • Flexural Strength: 5 N/mm2

Minimum Application Thickness

  • Bonded: 25mm
  • In contact with substrate: 30mm
  • Unbonded: 30mm
  • Floating Commercial: 40mm
  • Floating Domestic: 35mm
  • Underfloor Heating: 25mm minimum (30mm nominal) cover to pipes, heating elements.


Flowing Screed is supplied via a concrete plant in truck mixers or transmix trucks or as a bagged material.

Health & Safety

Some of the components of this product may be hazardous during mixing and application.
Please consult the relevant Health & Safety Data Sheets, available from us on request and provided with each delivery.

Environmental Benefits

  • Nominal recycled content of 36% (Gyvlon binder 98%)
  • VOC free
  • 100% recyclable

Our free flowing screeds are suitable for use in residential, office and administrative buildings as well as hospitals, food sector properties and schools. They are suitable to receive all types of plastic/vinyl and textile coverings as well as parquet, slabs/boards and tiles.

We are approved installers and have been trained and licensed to use free flowing screeds by all of the major providers:







Interior Flow™ supply and install flowing screed throughout the UK. We also supply and install a full range of acoustic and thermal insulation systems. All screeds are laser-levelled installed by our licensed applicators.

Please visit our contact us page. Alternatively contact our Estimating Team on 01789 730003

Facebook IconTwitter Icon

We Are Open For Business.

Interior Screed Ltd remains open to serve our customers

in light of COVID-19 | Official Government Advice |

On-Site Risk Assessement

For tender enquiries & quotations please call us

or email - estimating@interiorscreed.co.uk

8.30 AM | Mon-Fri

5.00 PM | Mon-Fri
Tel - 01926 679603 | www.interiorscreed.co.uk