The Underfloor Heating Store | Underfloor Heating

frequently asked questions

What is the difference between the heating mats and wood heating systems

Heating Mats:

Heating mats are the same cable as the loose cable kits (3mm loose heating cable rated @10 watts/m) already spaced out for you and attached to a fully adhesive mesh backing. Our heating mats come in 3 wattages:

200 watts per squa re meter this is the most powerful type of heating mat. It can be used beneath tiled or stone floors and is recommended for high heat loss areas such as conservatories. It should also be be used where laying onto a concrete floor when not using insulation boards. The maximum size of mat on 1 thermostat is 18m2

150 watts per square meter – this is a mid range powered mat which is suitable for most applications which can be used as a primary source of heating beneath most floor finishes. It should be noted that finishes such as Kardean or Amtico have a maximum of 150w per meter. The maximum size of mat on 1 thermostat is 24m2

100 watts per square meter – This is the lowest powered mat which is suitable for taking the chill off cold tiles – it is not suitable for a primary heating source. The maximum size of mat on 1 thermostat is 30m2

Heating mats are for use on a finished subfloor such as concrete screed or plywood and we recommend they are encased in either a flexible tile adhesive (if laying tiles) or a flexible levelling compound if laying any other floor finish.

Heating cable:

The loose heating cable is rated at 10 watts per linear meter and is the same cable used in the heating mats.

The cable comes on a drum and spacing must be manually measured (full instructions on how to do this are included in the kit).

In screed heating cable:

Must be encased in the finishing screed of the concrete floor (usually a minimum of 65mm as per Building regulations) with a minimum of 20mm of the screed above the cable. The same maximum outputs are recommended for the in-screed cable, that is, up to 200watts/sqm beneath tiles / stone and 160 watts/sqm beneath all other floor finishes.

Aluminium Wood Floor Heating Mats:

Are for use beneath laminate and engineered wood floors only. They are not suitable for solid wood floors.

The flooring must be fitted “floated” it must not be nailed or glued down. If using click together this is fine or if tongue and groove it must be glued along the joints. The biggest benefit of this system is that the wooden / laminate floor can be laid directly on top of the heating mat (there is no need to encase in tile adhesive or levelling compound).

Can i get my floor wet and can i use it in a bathroom

Yes. All our cables are waterproof and fully earthed; they can be used in bathrooms and wetrooms with no problem.

How wide are the mats?

The mats are 500mm wide and come in different lengths to suit the size of the room you require. For instance if you require a 4m2 mat kit, it would come on a roll of 8m2 long by 500mm wide. This covers 4m2. You roll out the mat and cut it when you reach the end of the room then flip it over and come back the other way.

How high will the system raise my floor levels

Our heating cables are 3mm thick, but you need to allow for your tile adhesive (5mm), your tile and any insulation board used.

Can we pick the products up from you ?

Yes. We sell online and also have a distribution centre in Billericay Essex, where a full range of products and accessories are always in stock along with specialist tile adhesives and levelling compounds. Please call 0800 077 8374 for our location.

What is the maximum wattage per meter square for my room?

Underwood – 140w per meter

Under Tiles / stone floors - up to 200w per meter

Under carpet or lino - maximum of 150w per meter

What wattage do i need?

If you would like to heat a standard room which is well insulated 150 watts or greater is required.

If you are heating a conservatory, which is considered high heat loss or a room with lots of fixed furniture such as a kitchen then we suggest 200w.

200w by nature heats up faster than the 150w so if you can use it then you may as well have the most powerful.

Will the heating system be able to heat the room sufficiently ?

This depends on a number of factors including room height and insulations levels in floor and walls, but if insulation boards are used (blueboard or marmox for tiles – depron or blueboard for wood) then the system should heat the room.

The system always works best if used with suitable insulation boards as this prevents the heat from going downwards instead of upwards. We understand that not everyone has the floor height to install a board so in this case you could use Thermacoat thermal paint, which does not raise the height at all.

Are your products CE approved ?

Yes, all heating cables come with a guarantee and are fully CE approved which means they are tested to rigorous standards.

How long will delivery take from when i order ?

All orders placed before 11am will go out for a next day delivery. In many cases we can get orders out much later than this. Please call us on 0800 077 8374 to see if we can help

Is delivery included in the price ?

Yes delivery is included in the price for heating kits. If ordering heavy item like tile adhesive then a delivery charge will apply, as this will be shipped on a pallet.

Is there a warranty with it ?

A lifetime guarantee is standard with all our heating cables. We offer a 2-year guarantee on the thermostats.

Can you connect up more than 1 cable or mat to a thermostat ?

Yes, our range of thermostats will switch 15amps so any combination of mats or cables can be connected as long as the total load does not exceed this. If you would like to switch a larger area with 1 stat then you can use a contactor to switch the load, please call for more info on this.

When using more than two heating mat / cables to connect into 1 thermostat it may be a little tight to get all the cables into the thermostat terminals – in this case you can use a junction box to connect them which can be positioned on the wall behind a blanking plate or similar.

Does electric underfloor heating cost more than convential heating to run ?

Electric underfloor heating (depending on insulation levels) can be the most efficient and cost effective heating method simply because the entire floor acts as the radiator and the heat rises from the floor rather than from a single area (like a radiator).

The thermostat regulates the power supplied and cycles on and off to maintain the desired temperature.

Typical running costs of a 250w system in a bathroom are approx 1pence per hour.

How safe is underfloor heating ?

As long as you follow the safe installation procedures as set out in our instruction manual, electric underfloor heating is very safe.

The heating cable we supply is twin conducting (which means you only have to connect one end) and double insulated using Teflon, waterproofed and has continuous earth screen.

The thermostats we supply use a floor probe that’s senses the floor temperature and shuts off the heating if it gets too high. Even if the probe were to fail the cables will only reach a max temp of 32c and so will never get hot enough to damage anything.

What are the main benefits of underfloor heating ?

The temperature of the floor surface is very much lower than the surface temperature of a conventional radiator.

There is no chance of hot water or gas leaks and no boiler to service.

No more unsightly radiators and more space in your room

Dust mites are reduced

How long will an electric underfloor heating system last ?

Our underfloor heating cables have a lifespan similar to that of mains electrical cable and should last the lifetime of your property (within reason and if installed correctly)

What tools do i need to fit it ?

You will need an ohm meter or multi-meter to check electrical resistance of the cables – a test should be carried out as soon as you take the product out of the box to ensure it has not been damaged during transit, then again just prior to fitting, then again before the final floor finish is laid.

You will need to fit:

Ohm meter

Tape measure

Pencil’s

Electrical metal back boxes 35mm deep

Stanley knife or similar sharp blade

Please be careful with sharp tools to ensure you do not cut the cable!!

How long will it take for the floor to warm up ?

This depends on your insulation levels in the floor. A well insulated house with marmox or blueboard insulation used can be warm in 20 minutes but if laid directly onto un-insulated concrete then it can take 1 hour +.

Laying onto plywood you should expect warm up time of approx 30mins.

Can underfloor heating be used under carpet or vinyl flooring ?

Yes it can be installed provided a layer of latex levelling compound is poured on the cables to cover them

Can i install it myself ?

The instructions we provide are detailed and a competent DIY’er should be able to install quite easily. Any aspect of electrical installation should be carried out by a competent person.

The underfloor heating store are registered NICEIC contractors and an carry out the installation for you if required. Call 0800 077 8374 for details

What electrical points do i need ?

For most small rooms the system can usually be connected to an existing household wiring circuit via a fused spur, for larger areas a single dedicated circuit from your distribution board will be needed. All electrical work must be completed by a qualified electrician who will be able to advise you on what you need. The use of an RCD is recommended.

How hot does the floor get ?

The floor will reach a temperature of approx 28c and will never feel too hot too touch.

What size heating kit do i need ?

You should aim to cover between 80-95% of the free floor space of the room. Covering less than 80 % of the FFS means you will end up with cold spots on your floor. We recommend that you measure the intended area to be heated and remove 10% of your total measurement to ensure that you don’t order too much.

Can i turn the system on straight away ?

We recommend that the Aluminium Heating mats (used beneath wood and laminate floors) can be used immediately but the temperature should be increased in small stages for the 1st couple of days.

The tile systems should only be turned on once the adhesive is completely dry, this normally takes 7 days.

What is an RCD ?

A residual current device (RCD), similar to a residual current circuit breaker (RCCB), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. Such an imbalance is sometimes caused by current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions. RCDs are designed to disconnect quickly enough to mitigate the harm caused by such shocks although they are not intended to provide protection against overload or short-circuit conditions.

Can i use normal tile adhesive ?

No. Normal tile adhesive is not designed to withstand the constant heat up and cool down of underfloor heating and will crack.

You must use flexible adhesives and grouts such as granfix fast set flexible tile adhesive

What size back box do i need?

You will require a 35mm metal back box for both types of thermostat