Q. Can you lay over chipboard floors?
A. It’s best to overboard chipboard with cement tile backer board as this will strengthen the floor against deflection. If you do want to apply Pro+Mat directly on to chipboard the chipboard must be treated against absorption of water and screwed down well. Choose a suitable tile adhesive specifically for chipboard.
Q. Can you lay over floorboards?
A. As long as the floorboards are screwed down, level and sufficiently able to bear weight and the deflection does not exceed L/360 for tiles & L/720 for natural stone, tiles can be laid directly on top of them in conjunction with PRO+MAT. A balanced moisture level of about 15% needs to be ensured before the mating is laid. It is recommended that if the floorboards are unstable, a suitably thick additional layer of tile backerboard should be added. Uneven places need to be smoothed out directly on the wooden foundation using a trowel of suitable dimensions.
Q. Can you use Pro Mat with Heated Screeds?
A. Promat mat itself, if properly installed, is suitable for an application with underfloor heating systems, as well as water heated underfloor systems.
The general service temperature range of the mat is -40° - up to +80° C and normally such systems have a temperature of around 40° C.
For electric underfloor heating it is recommended to lay the matting first and the electric underfloor heating mats directly under the tiles.
Heated screeds need more movement accommodation. The latest British Standard advise to install a Movement Joint to make bays of 40m2 or less with the longest side being 8m or less. This is in addition to those required at perimeters, across doorways and at changes in the substrate.
Any pre-existing Movement Joint in a sub floor must be carried directly through the tiled surface.
Screed substrates must have dried to a moisture content of <2% (CM test).
Grout Lines. Use good quality flexible grout. There is a minimum requirement of a grout width of 3 – 4mm – Wider is better. On large format tiles this is even more important. Large format tiles, (those over 400mm x 400mm), especially need wider grout joints on heated screeds.
Grout lines less than 3mm are not an option.
Q. Can you use any tile adhesive with Pro+Mat?
A. Not every tile adhesive is suitable for use with Pro+Mat! Only use high quality flexible thin-bed tile adhesives after first checking all properties relevant to use. We urge users to confirm suitability with their own trials before installation.
Please note that floors & uncoupling beds installed over underfloor heating systems may require upgraded materials - such as adhesives with higher adhesion strength and/or higher quality stoneware or ceramic tiles.
