Gyvtec Ltd installed water underfloor heating coated with an Anhydrite Liquid Screed to this a lovely property in Rendcome, Cirencester, Gloucestershire.
The existing floor was not level. Now some may just make up the levels in the depths of the liquid screed to different areas of the floor to make good, this is not the correct way to do things. Having large screed depth differences over the water underfloor heating pipes will cause problems with the floor slab not heating up evenly, leaving hot and cold spots in the room and may cause additional problems.
Firstly Gyvtec Ltd corrected the floor level issue using sand to bring to a level tolerance of 2mm. Installed a damp proof membrane, insulated using PIR insulation, polythene membrane, perimeter expansion and water under floor heating.
The property is currently being heated using an oil fired boiler. This is due to change to an air source heat pump in the future, so Gyvtec Ltd recommended the water underfloor heating pipes spacing was kept to around 100mm , rather than 200mm. This is because heat pumps heat the water to a lower temperature of 30-35 degrees centigrade, whilst an oil or gas boiler heat to about 50 degrees centigrade, so reducing the pipe spacing to 100mm in this older type of building, the floor will heat much more effectively.
We then installed 50m2 of Topflow liquid Screed (also referred to as calcium sulphate and anhydrite Screed) at a depth of 50mm over the under floor heating pipes.
After 7-10 days, Gyvtec Ltd remove the Surface Laitance using dust extracted mechanical grinding machine. This will prepare the surface for floor coverings and aid the drying process.
How long does liquid screed take to dry?
An approximate unaided drying time of 60 days for a job like this at a screed depth depth of 50mm. However, the underfloor heating canl be commissioned after 7 days and run through its cycle to reduce the Drying times by about 20%, full moisture testing will confirm when the floor is completely dry and ready for its final finish.
…For more information about liquid screed and water underfloor heating or to ast Gyvtec Ltd a project related question, please feel free to call us on 01452 689449.