Selecting the correct boards

To start with you will need to decide on the thickness of boards that you should use. The thicker the insulation board the more benefit you will experience, however this is at the cost of build height. In most circumstances a 10mm or 20mm board is ideal, however where build height is highly restricted a 4mm or 6mm board can be used. Once you have decided on the height of the board you will use, you should order enough packs to cover the area of the floor you wish to install them on plus another 5% to allow for off-cuts.

General installation guide

The boards are supplied in simple to transport packs. The packs are light enough for one person to carry and the boards can easily be cut with a knife. The boards should always be laid in a brick-like fashion (as with bricks in a wall) and once the boards are laid Heat Mat recommends taping up the joints between the boards with reinforcement tape to ensure a firm floor base.

Installing onto concrete or tile bases

When installing the boards onto hard floors they are affixed with a standard flexible tile adhesive laid with a notched trowel. The sub-floor should be primed and once the primer has gone off the boards can be secured down with the tile adhesive in a bed a couple of mm thick.

Installing onto floorboards or wooden bases (not 6mm boards)

10mm and thicker boards are suitable for securing wooden and chipboard floor bases and in these circumstances they are screwed down with at least 21 screws per board. Screws with 35mm washers should then be used to secure the boards at 300mm centres.

Waterproofing in wet rooms

If the boards are being used in a wet room to provide the tanking system all joins should be waterproofed with a silicon sealant. The simplest way to do this is to run a bead of sealant along the edge of the board before it is laid and then push it up to the abutting boards to complete the seal. All joints must still be taped with reinforcement tape afterward.

Coated vs uncoated boards

Heat Mat Underfloor Heating Insulation Boards are concrete faced which provides many benefits over uncoated non-reinforced boards. One of the main benefits of coated boards is they resist point loads so are not crushed during installation. They also prevent broken tiles and cracked grout if significant weight is placed on the finished floor, which can be a problem with uncoated boards. Coated boards provide Class O fire protection (uncoated boards offer no protection) and the concrete layer also helps the heat from the heating cables to spread providing an evenly heated floor.