Hi,
I wish to tile in a hallway over existing floor boards. I do not want to raise the height by too much and I am wondering if I overlay 4mm marine ply screwed into the joists and boards, and a flexible adhesive can give a satisfactory result.

The alternative is to remove the existing boards and fit 18mm marine ply, this is something I am not in a rush to do if the 4mm on top of boards will be just as good.

Thank you,

Peter

If you're using a ceramic or Porcelain tile then 12mm ply minimum over floorboards.

If removing boards completely then it's got to be 25mm ply I'm affraid.

Hi Bathstyle,

Pardon my ignorance, what is the purpose of the plywood?

Is it to stiffen up the floor? Is there a more forgiving adhesive for floors without the required stiffness?

The floor is ~ 2m X 2m and it certainly seems solid to me in comparison to tiled kitchen floors I have looked at.

Many thanks,

Peter

It basically holds the floor together, strengthens it and lets it move as one complete piece, any localised movement in the floor (if tiling straight on floorboards) and the tiles/grout may crack.

A lot of Adhesive manufacturers recomend using an elastomeric adhesive straight onto floorboards but personally I don't like it and it costs an absolute fortune to buy