Foil Underfloor Heating

Luxury warm floors can be achieved easily with BN Thermic’s F-series foil underfloor matting. Below walks you through the matting along with the energy saving impact of insulation boards and thermostat control.

Underfloor Heating – Laminate or Engineered Wood Floors

Underfloor heating in a room with a laminate or engineered wood floor can provide an economic means of heating a room.

Foil Underfloor Heating Mats

BN Thermic foil heating mats are a very simple means of heating a laminate or engineered wood floor. The mats consist of heating cables sandwiched between two layers of aluminium foil ensuring excellent heat distribution.

The mat is pre-terminated with a 3m power lead and the web is installed onto a layer of I-Board insulation/underlay. The I-Board helps to limit downward heat loss as well as providing a non-abrasive surface for the mat to rest on. The final floor surface is applied directly onto the foil mat without the need for compounds or adhesives.

Foil heating mats can be installed in any room including bathrooms.

Selecting a Suitable Mat

When selecting a mat, the objective is to cover as much of the free floor area as possible. Mats should not be installed under fixtures such as kitchen cabinets and shower trays. As a rule of thumb, we suggest selecting a mat with an area approximately 10% smaller than the free floor area.

BN Thermic supplies foil mats covering areas up to 14m². However, for larger rooms, it is common practice for two or more mats to be used. Generally, the mats are connected in parallel and controlled by a single thermostat.

Thermostatic Control

Each room will require its own programmable thermostat. BN Thermic offer a range of suitable thermostats to meet different aesthetic requirements, tastes and budgets. However, all BN Thermic programmable thermostats share the same key features.

For most rooms, primary temperature control is by means of the thermostat’s built-in temperature sensor. The thermostat’s floor probe, which is installed at the same level as the foil mat, will then act as a safeguard ensuring that the floor does not become uncomfortably warm.

In some installations, notably bathrooms, it is common for the thermostat to be located outside the room being heated. In these circumstances, the thermostat’s built-in air sensor should be passed and temperature control should only be by means of the floor probe. The adjustment from ‘air and floor’ to ‘floor only’ is simple to achieve and detailed instructions are provided with the thermostat.

Foil Underfloor Heating FAQs

What type of flooring can foil underfloor heating be used with?

Foil heating mats such as BN Thermic’s F-Series are designed for use under floating floors such as laminate or engineered wood. For tiled floors, we would suggest using a cable mat system such as BN Thermic’s M-Series. Installing foil underfloor heating mats under floating floors does not require adhesives or self-levelling compounds.

Can I use foil underfloor heating as the only heating in a room?

F Series foil heating mats deliver 140W per square metre. In most rooms this will be sufficient to provide a sole source of heat. In rooms with high heat loss, such as some conservatories, supplementary heating may be required.

How do I install electric underfloor foil heating mat?

There are three layers in a foil mat underfloor heating system. First you must cover the entire floor with a suitable underlay/insulation material. Secondly, the foil mat is stuck onto the underlay/insulation and finally the floating floor (laminate or engineered wood) is installed onto the heating mat.

Comprehensive installation instructions can be found in the download section.

How many insulation boards to I need for a foil underfloor heating installation?

Foil heating mats such as BN Thermic’s F Series must be installed onto suitable underlay/insulation material. This material provides a non-abrasive surface for the foil mat to sit on and helps limit downward heat losses thus improving economy.

BN Thermic’s I-Board is ideal for use with foil heating mats. Each individual board covers 0.5m² and can be easily cut to the size and shape required. To calculate the number of I-Boards required, simply calculate the total floor area in m² and divide the answer by 0.5. So, for example, if the total room is 8.9m², you should divide this number by 0.5 to get 17.8 meaning that you would need a minimum of 18 I-Boards. In fact, we would probably recommend ordering 19 boards to make allowances for any inaccuracies in area estimation or installation.

How much does underfloor heating cost to run?

If we assume an electric tariff of 13p/kW/h, F Series foil heating mats will cost 1.82p to run for each heated square metre on full power. This simple figure will allow you to calculate the absolute maximum running costs for your room, depending on the size of the room and the hours per day you wish to heat the room.

Once the underfloor heating has produced the required room temperature, its output will be regulated by a thermostat. At this stage the running cost per metre will be greatly reduced.

Now, there are a few simple things that you can do to reduce this cost.

Insulate the floor before installing the heating
Keep windows and doors shut
Use a good quality thermostat and investigate energy saving features such as ‘optimum start’ and ‘open window detection’.
Make sure that your thermostat is set to the lowest acceptable temperature and is programmed to be on for the shortest acceptable time.

These ideas may sound obvious, but they really will make a big difference!

Can the heating cable be shortened or extended?

Foil underfloor heating mats contain a heating cable that runs, in evenly spaced loops, the entire length of the mat. This cable must not be cut or shortened. The foil mat itself can be cut to allow the heating to be manipulated to suit the shape of the room. Each F Series mat is fitted with a 3m power cable which connects the mat to the thermostat. This power cable can be shortened or extended to suit.

What total thickness will a foil underfloor heating system raise my floor?

The combined thickness of I-Board underlay/insulation material and F Series foil heating mat is approximately 7mm. Therefore the total increase in floor height will be approximately 7mm plus the thickness of the laminate or engineered wood flooring you have selected.

Can furniture or rugs be placed on a heated engineered wood or laminate floor?

It is very important that solid, permanent or floor fixed furniture is not positioned on a heated engineered wood or laminate floor. These items can trap heat and cause localised overheating.

For the same reason, thick rugs, bean bags, dog beds and other items with high insulation values should be avoided.

Can foil underfloor heating be used with carpet?

We would not recommend foil underfloor heating with carpets. A more suitable system is the M Series cable mat which can be covered in a self-levelling compound. Once the compound is completely dry, a low tog carpet and underlay can be fitted on top.