What Is The Minimum Screed Thickness Over Underfloor Heating?

I’m Andy Parkin Managing Director of the Multi Awarding Winning Speed Screed.  Today I would like to talk about Underfloor Heating screed thickness minimum.

When we talk about underfloor heating in this example we are talking about the “wet” system.

All the following information is based on 15mm pipes, other than 10mm pipe with the low-profile system.

Screed thickness minimum is based on the “high spot” in the building, assuming that a level floor screed is required, and not a profile of the substrate.

The “low spot” will mean an increase in depth.

Liquid Screed Depths (calcium sulphate).

• 35mm to 45mm total depth of screed inclusive of pipe (dependant on product chosen).

Low-Profile Systems

• 22mm total depth of screed

Traditional Sand And Cement (1:3 & 1:4)

• 65mm total depth of screed

Hydraulic Binder Screed (Fast Drying)

• 55mm total depth of screed

Retanol Xtreme (Fast Drying)

• 45mm total depth of screed

Laying screed thinner than the recommended minimum leave the floor open to failure.  The typical design life of screed is 50 or 100 years, and with screed being laid outside that of the recommended depth will surely leave the screed short of its design.

I hope you now have a better understand of the underfloor heating screed thickness minimums, however if you have any other questions please contact us.