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What is a Screed Underfloor Heating System?
Screed underfloor heating systems are most commonly used and have the advantage of being the most efficient due to the lower flow temperatures. Insulation is placed on top of a ground bearing slab, block and beam or suspended concrete floor, with a vapour barrier / slip membrane positioned under the floor heating on top of the insulation. This is to protect the screed from reacting with the insulation product.
Cliprail is then fastened to the insulation using cliprail clips with the PEX pip fixed into place using the pipe clips. The cliprail also raises the pipe away from the insulation allowing the sand / cement screed to flow all the way around the PEX pipe, ensuring full conductivity and maximising the thermal mass.
Edge insulation should be laid to prevent a thermal bridge between the screen and the exterior wall. The screed must comply with British Standards Code of Practice.
Additional cliprail, clips and pins will be required if using a flow-screed as the liquid will try to float the pipe.
Which Screed Underfloor Heating Systems to Choose?
Underfloor heating installers provide a variety of underfloor heating systems suitable for screed installation both on a bespoke or kit form basis. Our underfloor heating FAQs have answers to a lot of the most common questions you might have about which type of system to use.
Flow screed
A Flow Screed system is very similar to a standard screed system but due to the higher density requires additional fixings to fasten the PEX pipe so that the pipe does not float when the screed is installed. Worth noting here is that if you cannot use screed due to the nature of the flooring in any given room, you can use plate underfloor heating for the same effect. Warmup underfloor heating uses electricity to generate its heat and is an alternative you might want to consider.
Screed on Mesh
Screed on mesh is typically fixed onto A412 Builders Mesh using cable ties. The installed system is then covered with a standard screed.
Most systems are available for use with heat pumps or boilers and full specifications can be provided on request.
PUG
This is generally a thinner screed laid between existing joists.
If you would like to know more about underfloor heating, take a look at this article, which explains in more details how such systems are designed and installed.