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Installation Manuals


It’s essential to make sure that your calculations are correct before ordering your underfloor heating system, as our cables cannot be cut during installation and we cannot provide refunds for items that have been unrolled, cut or damaged.

If you need any advice before ordering your heating solution, you can contact a member of our design or technical team, who will be more than happy to provide you with advice. We are available seven days a week, and most of our staff are fully qualified electricians and plumbers who have experience in installing underfloor heating, so you know that you will only get professional advice.

We would recommend that, when you take any measurements, these are done so in metric (metres) and that you double check these before placing your order.

Below, we’ve provided two examples of how to measure for your underfloor heating:

Example 1 Underfloor heating for a normal-sized bathroom

  1. Firstly, you need to calculate the area in square metres by measuring the length and width of the room in metres and multiplying these figures together. For example, your bathroom may be 2m x 2.5m, so the area is 5m2 (2m x 2.5m).
  2. Next, you will need to subtract the area taken up by any fixed items of furniture that cover the floor (bath, sink pedestal, toilet etc). In the same way as the example above, calculate the area taken up by each item and take the total figure away from the area of your room. For example, a typical bath measures at 700mm x 1700mm (or 1.19 m2).
  3. Once you have done this, you will need to remove an additional 10% to allow for a 75mm gap around the edges of your heating installation.
  4. So in this example, our room is 5m2 less 1.19m2 for the bath, which gives us 3.81m2 and by removing an additional 10% (0.38m2) we arrive at a figure of 3.43m2.
  5. For a heating mat system, the closest kit size would be 3m2 or, for a loose cable system, it would be 2.9m2 to 3.7 m2 (remember that you should under-order rather than over-order, as cables cannot be cut during installation).
  6. When insulating the floor before laying your heating system, you will need to calculate the area without the 10% removed around the edges, as your insulation should be flush to the edges of your room.
  7. If you are selecting a loose cable system, then you may notice that each kit covers a range of floor areas. This is because the cables’ spacing can be adjusted to vary the heat output of your system:
    • 6cm spacing between the cable loops = 165w/m2.
    • 6.5cm spacing between the cable loops = 150w/m2.
    • 7.5cm spacing between the cable loops = 130w/m2.

Example 2 Underfloor heating for a normal-sized kitchen

  1. In the same way as our first example, you should first measure the length and width of the room in metres to give you the total area. In this example, our kitchen is 3.5m x 4m, thus the area would be 3.5m x 4m or 14m2.
  2. Again, we need to calculate the space taken up by fixed items of furniture, such as floor-standing units. The kitchen has a 4m run of 600mm deep units, thus taking up 2.4m2 of floor space (0.6m x 4m).
  3. Taking off an additional 10% to allow for a 75mm gap would reduce our total floor area from 14m2 to 10.44m2 (14m2 – 2.4m2 – 10%).
  4. The total area to install is therefore 10.44m2 and the 10m2 mat would be the best selection, or a loose cable kit of 8.8m2 to 11.22m2.
  5. Again, when installing insulation boards you do not need to take off the 10% for the gap, as your boards will need to be flush with the walls of your room.