Concrete Floors
 
In concrete screeded floors, the screed acts to diffuse the heat across the surface providing an even temperature at the floor surface.


Depending on the type of building, construction, standards, there are a number of methods of laying the underfloor heating pipes in concrete floor structures.

The most popular method of installation is as follows:

a. A concrete slab (or suspended beam and block construction) is laid over a damp proof membrane.
b. A 20mm thick piece of insulation is fixed to the perimeter (external) walls, to a height to include the depth of floor insulation and screed. Whilst the edging insulation may be on show it is covered by wall plastering and skirting boards.
c. Floor insulation laid to the whole area, joints are taped to prevent the ingress of screed between the insulation boards.

The floor is now ready for the underfloor heating pipework installation.
 
 
We recommend you use a 50mm layer of Polyurethane insulation. If there is not enough space for 50mm insulation, 25mm is recommended. We recommend Polyurethane as it out performs polystyrene and its greater density allows use of clip fittings.
 
If you use polystyrene insulation (50mm) it is recommended that you install wire mesh on top of the insulation and tie the pipe to the mesh.

For other floor constructions please contact our technical department.
 
Please note some insulation manufactures require additional separating membranes, please contact your chosen supplier for advice.

The pipe is laid at 200-300mm centres dependent upon design.

Care must be taken to protect the pipework whilst installing the screed.
 
 
Finally the floor finish is laid. Underfloor heating works well with almost any floor finish; tiles, carpets (use carpets with a resistance of less than 0.15 m2K/W), timber floors, plastic etc.
 
 
The floor coverings and the adhesive must be suitable for the temperatures that underfloor heating will provide, the maximum temperature they need to resist is 40°C. Always check with the manufacturer of the floor covering if it can be used for underfloor heating. Timber floors need to have a moisture content below 10% to avoid shrinkage. The system must be operated for 21 days with a very low temperature to dry the screed, then the floor covering can be laid.