XPS hard insulation


6mm Thick

Will bounce your heat upwards sufficiently if height is an issue


10mm Thick

Recommended as standard. Will give that little extra insulation


20mm Thick

A little far for simply insulating. However, perfect for building up floor heights


XPS Board

30 ton compression ratio. Designed for use under tile and stone

XPS Hard Insulation Boards -Under Tile insulation board

Underfloor hard thermal insulation boards are designed for use directly under tile, stone, wood and laminate floors. It can also be used under mosaic, vinyl and carpet flooring but must first have a suitable 9+mm layer of flexible self leveling installed over prior to the vinyl or carpet being fitted. The insulation comes in 6, 10, 20mm & 30mm depths. The steps below are to help guide you through the installation process.

1: The sub-floor whether concrete or wood should be made suitable for the chosen floor covering, (ie; tiles) prior to any boards being fitted. The boards are designed to provide increased insulation levels not structural rigidity.

2A: For Wood and Laminate Floors. Once step one is completed and the floor is level, clean, dust and debris free the boards are ready to be laid. The boards can be laid directly over the sub floor making sure to butt the boards tightly together so not to leave gaps between boards and round the edge of the room. This will help prevent movement and maximise the floor insulation. Once the floor is fully covered the heating, wood or laminate can be fitted directly over the insulation boards.

2B: For all other floor types. Make sure the floor is level, clean, dust and debris free as only then the boards can be laid. A suitable floor primer should be applied to provide a good fix for the adhesive (see adhesive fitting instructions).

3: Using a standard 1 part flexible floor tile adhesive, suitable for use with the sub floor construction, (ie; wood or concrete) spread a thin full bed of adhesive over the floor. It is advisable to work in board size areas at a time and rather than using a typical floor tiling trowel, to use a smaller notched trowel such as a 6mm notch size which will increase the coverage of adhesive per bag.

4: Once the adhesive is spread lay the insulation boards over the freshly spread adhesive using a large, rigid, flat trowel/board to press the insulation boards down flat into/onto the adhesive. Care should be taken to make sure the boards are fully pressed into the adhesive and no air pockets or gaps are left under the boards. All boards should be butted tightly together making sure to achieve a full floor coverage. It is good practice to stagger joints between boards and if necessary the flexible floor adhesive can be used to fill any small gaps between boards.

5: If boards need to be cut to size this is easily done with a sharp Stanley knife.

6: Once the boards are laid and the adhesive is set, care should be taken not to apply excessive point loads to the insulation until the tiles or leveling has been installed. Small dents and damage caused to the surface of the boards are quite normal and of no concern. If however the boards are to be left exposed for long periods of time or other work is to be carried out over the boards they should be covered with sheets of ply or other hard sheet material to minimise the chance of damage.

7: It is advisable to fit the final floor covering as soon as possible once the insulation has been installed. When fitting the chosen final floor covering it is advisable to work on top of a hard board. This will help prevent damage to the insulation when the work is being carried out.

8A: Wood and laminate flooring. (If not following step 2A) Both under floor heating and wood type tongue and grove flooring can now be fitted directly over the insulation in accordance with the manufactures fitting instructions.

8B: Tile & Stone Flooring Tiles measuring 150 x 150mm or bigger can be fitted directly over the insulation. A suitable flexible tile adhesive should be used as directed by the adhesive manufacture. The tiling should be carried out in the normal way making sure to fit the tiles with a full bed of adhesive, (never dot and dab tiles).

8C: Fitting vinyl, carpet or mosaics. When fitting non interlocking rigid sheet material over the insulation boards an 9+mm layer of flexible leveling
compound should first be fitted over the insulation. This will provide protection from high point loads as it will spread the weight over the insulation surface allowing the subsequent layers to be fitted. The leveling should be fitted in accordance with the manufacturer’s instructions.