DIY Supermarket

When installing an underfloor heating system, it is important to also install underfloor heating insulation.  The purpose of the insulation is to ensure that the warmth generated by the system is reflected up through the floor and into the room, not down into the sub-floor.

One way to insulate an underfloor heating system is to use polystyrene boards.  This type of board is quite strong and conducts very little heat.  Polystyrene boards are designed to be used on top of cement screeds or solid concrete sub-floors.  You will need to use a different type of underfloor heating insulation for wooden sub-floors.

For wooden sub-floors, tile-backer boards should be used.  Tile-backer boards have a polystyrene core, which is surrounded by glass fibre mesh, which is then coated with reinforced polymer cement.  This is to make the tile-backer board rigid.  It is attached to the wooden sub-floor with a flexible adhesive. 

The insulation boards are attached to the sub-floor with an adhesive.  The underfloor heating cables are laid over the insulation and finally the floor is fixed on top; this is also attached with an adhesive.

Tile-backer boards may also be used with concrete sub-floors, but should only with electric underfloor heating systems.  Polystyrene boards may be used with either electric or water underfloor heating systems.

Although it is strong, underfloor heating insulation is easily cut with a sharp knife.  It is also waterproof, lightweight for easy handling and resists rot.

Underfloor heating insulation is an essential part of an underfloor heating system.  Without it, you will lose a substantial percentage of the heat generated.