How to Lay Underfloor Heating
October 31, 2013.
Underfloor heating is unique in the way it evenly distributes heating around a room. First employed by the Romans in their villas, it can be installed under tiles, laminate and even wooden flooring. If you are looking to have underfloor heating fitted in your home, you may choose to call in the experts or to pick up a DIY kit and do the job yourself. This can be done fairly inexpensively with a reasonable level of skill so, for guidance on how to get the job done, follow our simple guide below. Just remember: always have any wiring checked by an electrical professional before connecting it to the mains.
What you will need:
- Your choice of underfloor heating
- Adhesive spreader
- Spirit level
- Cold chisel
- Club hammer
- Fixing tape
- Tape measure
- Tub of tile adhesive and tiles
- Insulation board (if laying onto concrete)
If you are laying onto concrete you will need to prepare the area first in order to maximise the performance of the system you install. This may involve installing an insulation board, but at the very least you should paint the floor with thermal primer to give a dust-free surface for laying out, this will help the tile adhesive take hold more easily and increase lateral heat transfer.
Your first priority is planning the position of the wires. To do this you will need to plot the size of the room compared with your kit. You will need the ends of the wires placed conveniently near a power supply, so you may need to seek some electrical advice. The spacing measurements you choose will depend on the size of your room, but generally they should be laid out at according to the specifications of the kit, which may come with pre-spaced taping to guide you. Some kits use plastic mesh to hold wires at regular spacing, while others require you to fix the wire with spaced tape to ensure a good spread of warmth. You will also need to plan out the laying of your flooring over the system in order to fit it correctly. Read the how to tile a floor for further guidance.
1) Lay the wiring
Read the manufacturer's instructions before laying your wires or mesh system across the surface of your floor. Be careful not to lay matting under kitchen units, while avoiding any overlapping wiring. Once you have laid out your wiring, you should secure it using fixing tape if required.
2) Fit the sensor
The next step is quite technical and will require checks from a qualified electrician once complete. Your kit should come with a sensor or floor probe that needs to be wired into your thermostat. Your sensor should be fitted inside an electrical conduit and placed in position near the thermostat. You will need to fit the conduit by chiselling and then sealing its tip with silicone sealant. This is an important step that stops the tile adhesive setting around the sensor and preventing it from working.
3) Connect to power supply
Your system is now ready to be connected to the power supply; this should be performed by a qualified professional who will need to check your system is set up correctly first.
4) Lay the flooring
It's now time to lay the flooring on top of your heating system. Using your adhesive spreader, apply the adhesive across the matting and fix your floor tiles securely. If your system is suitable for use with a wood or laminate floor and you are opting to install one or the other, you will need to follow a different process and may need to fit an insulation board under the element.
5) Finishing touches
Now you’re heating and floor is laid, you can re-fit any skirting boards and adjust any doors to fit over the new floor level.