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If you have any questions or would like assistance, please contact our technical team:
- Email: technical@netweber.co.uk
- Telephone: (01525) 722 100
Our technical team is available Monday to Friday, 8:30am until 5.00pm.
Underfloor heating can cause an array of issues if not tiled onto correctly, from cracking due to heat expansion to damaging wires with a trowel.
There are two solutions for this problem, one for each electric underfloor heating and piped underfloor heating.
Our highly polymer-modified levellers, adhesives and grouts have enough flexibility when set to accommodate thermally induced movement.
A floor leveller can be used to cover and protect the wires that otherwise could get damaged during application of the adhesive, and can stabilise movement in the floor.
First, ensure your substrate is rigid, sound, clean and dry.
For solid substrates: Prime with weber PR360 and allow to dry.
For wooden substrates: Ensure it is capable of supporting the expected load and probable dynamic load, without excessive deflection. You can take up existing boards and stiffen them with noggings to add extra strength. Alternatively, extra rigidity can be achieved through overlaying the existing timber boards with either WBP plywood or tile backer board. Plywood should be at least 18mm thick, primed on the reverse face and edges with weber PR360 and screwed every 300mm. Tongue and groove or floorboards must be screwed to joists using two screws per board at every joist. All boards should be primed with weber PR360. All joints between boards should be filled with weberjoint silicone sealant to prevent leakage during application.
Install underfloor heating system in accordance with the manufacturer's instructions and test that it works. Turn it off and allow to cool.
Apply weberfloor flex self-levelling compound up to 50mm deep or until the warming elements are covered by at least 3mm (10mm minimum for wooden substrates). Allow 3 hours before foot traffic.
Fix the tiles into a bed of weberset pro lite - rapid, weberset rapid SPF or weberset SPF at least 3mm thick (5mm thick for wooden substrates). Leave joints at least 3mm wide for grouting and make provisions for movement.
Grout the joints with weberjoint wide flex or weberjoint premium and use weberjoint silicone sealant to fill perimeter movement joints.
Keep the heating/warming system turned off for at least 5 days to allow the cement to cure. Bring the system up to its operating temperature gradually in stages over a few days, do not exceed 27°C and no more than 5°C per day.
If you have any questions or would like assistance, please contact our technical team:
Our technical team is available Monday to Friday, 8:30am until 5.00pm.
Piped heating systems are buried in reinforced cement/sand floating screeds of not less than 65mm thick. If a polymer-modified levelling screed is used it must cover the pipes by a minimum of 10mm. Our highly polymer-modified adhesives and grouts have enough flexibility to accommodate thermally-induced movement.
The heating pipes should be installed according to manufacturer's instructions, fixed down and tested prior to being encapsulated in a screed or levelling compound.
If the pipes have been laid in a reinforced cement/sand screed this must be allowed to dry fully prior to tiling. A sand/cement screed should be left for 3 weeks with the underfloor heating off to dry. After this period the heating system should be turned on and raised by a maximum of 5°C/day until the maximum recommended operating temperature is achieved. This temperature should be maintained for 3 days and then the system turned off and the screed allowed to cool to 15°C before tiling commences.
If weberfloor flex levelling compound is used to cover the pipes instead of a cement/sand screed, the drying time will be considerably shorter.
Ensure that the cured surface of the floor is rigid, sound, clean, dry and free from any contaminating barrier. Prime with weber PR360 and allow to dry.
Fix the tiles into a solid bed of weberset pro lite - rapid, weberset rapid SPF or weberset SPF at least 3mm thick. Leave joints at least 3mm wide for grouting and make provisions for movement.
Grout the joints with weberjoint wide flex or weberjoint premium and use weberjoint silicone sealant to fill perimeter joints.
Keep the warming system turned off for at least 5 days to allow the cement to cure. Bring the system up to its operating temperature gradually in stages over a few days.
If you have any questions or would like assistance, please contact our technical team:
Our technical team is available Monday to Friday, 8:30am until 5.00pm.
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