• 1.1 As a floating floor is not supported by flexible NC sealant joists, any applied load creates significant movement over a big area. This can be felt as bounce in the floor when it is walked across. As the applied load increases so does the severity of movement.
• 1.2 The edges of a floating floor are even more susceptible to exaggerated movement as they are not supported and any applied load is spread over a smaller area.

If the adhesive used to fix the tiles is not flexible or thick enough to absorb the amount of movement, the tiles will either delaminate or crack. Large tiles will exacerbate the deflection across each tile’s width.



If a joint between wooden boards of a floating floor is not correctly located or fixed, it will be susceptible to highly localised movement which will crack the tile along the joint.

If the boards of a floating floor are not tongue and grooved, they are not suitable for tiling.



When a floating floor is over-boarded to add rigidity, the extra board has to be securely attached to the original boards. If nails are used, the constant movement of the floor can cause them to work loose, press on the underside of the tile and cause cracks to form. If the screws/nails used are too long they can bottom out on a rigid surface under the floating floor and create a column, over which tiles will crack.

Overboard with plywood or tile backer-board

Although relatively small tiles can be fixed directly onto small areas of tongued and grooved floating floors using specialist products such as weber.set WF21 or weber.set rapid flex, a much more secure solution is to fix a second board over the existing timber.

This increases the rigidity of the floor and prevents localised movement, thus making it a far better substrate for tile fixing. If a water-resistant tile backer-board is used to overboard, it will virtually eliminate any moisture related movement.