Topflow Screed A Thermio

The guaranteed ultra-efficient liquid screed / free-flowing / gyvlon screed for underfloor heating systems.

Thermio+, anhydrite environmental liquid screed solution, has been developed to further improve underfloor heating systems by creating the first liquid / gyvlon screed specifically designed to complement both water underfloor heating and cooling systems.

Topflow Liquid Screed A Thermio+ is the only liquid screed with a guaranteed thermal performance.
This technology coupled with an underfloor heating or cooling system guarantees pipe encapsulation and an emitter which will give;

  • Performance – up to 30% increase in the thermal emission value for maximised performance of the underfloor heating system once your Gyvlon Screed is installed.
  • Comfort – up to 80% thermal diffusivity for a much faster ramp-up in temperature, greatly improving immediate and long term comfort
  • Savings – up to 8% savings on heating bills
  • Programme efficiency – 20 day reduction in screed drying times when compared to conventional flowing screeds
  • All the normal benefits of Topflow Screed A liquid screed / Gyvlon screed products
  • Very high fluidity for fast installation of your liquid screed
  • Minimum SR2 surface finish
  • Greatly reduced cracking and no curling
  • Maximum bay size 300m2
  • No reinforcement
  • No need for a curing membrane
  • Typically 36% recycled content
  • High and guaranteed thermal performance both in heating or cooling modes
  • Low inertia (nominal thickness 20mm cover to pipes)
  • Red colouration – the guarantee of the right product by Gyvlon Screeds
  • Topflow Screed A Thermio+ liquid screed / gyvlon screeds is extremely beneficial for your water underfloor heating systems
  • Enables a much faster rise in temperature thanks to its high thermal diffusivity (up to 80% more than a cement screed), providing quicker response to thermostat changes.
  • Greatly improved comfort as the liquid floor emits the heat in a more efficient and homogeneous way thanks to the exceptional thermal emission value of the liquid screed – up to 30% more, maximising your underfloor heating performance
    • Allows your boiler or heat pump to work with greater efficiency therefore creating considerable savings on your heating bill of up to 8%

Mechanical strength: C30 F8
Thermal conductivity (nominal value) : λ=2,5 W/m.K Thermal emission coefficient : KH =7,42 W/m .K Diffusivity:D=1,0.10 m /s
Wet density: 2200kg/m
Dry density: 2000kg/m
Nominal thickness above the pipe: 20mm
Minimum thickness by substrate:

  • Unbonded:30mm
  • Floating liquid screeds / gyvlon screeds – residential:35mm
  • Floating liquid screeds / gyvlon screeds – commercial:40mm
  1. Independent study by Cardonnel
  2. According to Avis Technique / DTA CSTB N° 13/12- 1184, with a minimum of 2.3W/m.K guaranteed for thermal calculations in whole UK
  3. Calculation according to EN1264. Minimum value stated at the present document edition

Topflow Screed A Thermio+ liquid/flowing screed is produced using Gyvlon screed binder, which is manufactured from an indus-trial by-product.

Topflow Screed A – average 36% recycled content.


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