Raychem Underfloor Heating Suitability & Sizing

 Raychem Underfloor heating suitability for your floor covering.


Click here to view the Raychem handbook.


 Raychem Underfloor Heating.

Floor covering.


Natural stone.




Plastic floor covering.

Textile floor coverings.**


T2Red in filler.

 Very good.  Very good.  Very good.  Very good.  Very good.  Very good.  Very good.

T2Red with T2Reflecta.


T2 QuickNet.*

 Very good.  Very good.  Very good.  Very good.  Good.
 Very good.  Very good.  –  –  –  –  –

T2 Blue.



 Very good.  Very good.  –  –  Good.  –  –
  Very good.   Very good.

Isolecta with T2QuickNet


  Very good.   Very good.  –  –  –  –  –


*T2 QuickNet 160 not on wooden sub-floors.

**must be suitable for underfloor heating. (maximum resistance to heat transfer 0,15m2K/W).


Working out Raychem T2 Red Cable requirements :-

Which power output do I need?

1. New construction – good insulation.

35 W/m2 – 60 W/m2.

2. Renovation – good insulation.

60 W/m2 – 100 W/m2.

3. Insufficient insulation – more output required.

> 100 W/m2.

The above values are for comfort heating. Make a heat-loss calculation if in doubt. (Insulation, room size, number of windows etc.) or contact us.


1. Select the required power output and required cable length per m2.

The tables below show the spacing and required cable length per m2 and the spacing between the cables. The power output gives approx. 20-25⁰ C (depending on the subfloor construction). For higher output please contact us on 01484 859700.

2. Multiply the cable length m2 by the total floor surface (m2).

Example: Renovation of bathroom (5m2) with tile floor.

  • Select 15mm cover plus tiles.
  • Select 80 W/m2 (7 m cable needed per m2). Spaced between two cable runs is 140mm.
  • Required cable length is 7 x 5 = 35m T2 Red heating cable + 2m for connection in junction box = 37m.
















New Construction.


















Raychem underfloor heating suitability

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