Under Tile Heating

Underfloor heating started many years ago. It wasn’t until the Romans arrived that underfloor heating was put into use to heat the floor and walls. During this time the Romans built rooms with floor slabs laid on to raised pillars allowing warm air to circulate beneath the floor. The furnace was normally located at the bottom of an exterior wall; the draught would pull the heat under the floor and up through the walls to chimneys which were in the corners of the rooms.

Today of course we don’t do it like that anymore but the principle still remains the same.

Modern electric underfloor heating systems usual consist of a heating cable or carbon film. The heating cable comes in a couple of different forms, mainly on a cable mat or as a loose cable. A few years ago the most popular form was a loose single cable supplied on a spool. This method required you to work out the cable spacing by dividing the floor space by the length of the cable. You would then start about 5cm in from the edge of the room and loop the cable up and down, leaving enough room and cable to return to the starting point, this then completed the circuit. The trouble with this method is its very time consuming, more often than not you would end up with either too much cable or not enough, meaning pulling up the cable and re-spacing, and also if you didn’t get it right there is a real risk of creating hot and cold spots.

Hot and cold spots exists because the heating cable has at one point being spaced too close together therefore creating a hot spot, or visa versa to far apart creating a cold spot.

To over come this problem manufactures have now created “cable mats” with a “built in return”. Built in returns mean you don’t have to complete the circuit as both the start and finish wire are combined into the one cable, this has many advantages over the earlier cable in the form of not having to leave enough room and wire to fetch it back to the starting point.

Under tile heating mats are simply a loose cable attached to a nylon mesh and pre-spaced to give you different watts per m²; the most common mats usually give you about 150, 160 or 200w per m². These mats save you time during the installation, and lesson the risk of hot and cold spots. Cable mats normally suit square/rectangular rooms, but with most mats you can remove the cable and revert back to the loose system, keeping the original spacing you can stick it to the floor to get around irregular gaps or simply were the mat wont fit in you can pull the cable off and tape it to the floor.