In the kitchen, part of the floor are these t&g floorboards. We are tiling the kitchen floor. I was going to pull up these floorboards for possible salvage and re-use elsewhere. A lot of work as they are nailed in with 2" wire nails through the tongues !
But then I thought, why bother? Why not tile straight on top but on inspection I see that the joists are floating on a white polystyrene slab.
My concern is flexing of this substrate causing cracking at the joins between the tiles in the grout. It's very hard to feel if there is any flexion. The floorboards are 20mm thick.
I see three options :-
1) take up the floorboards as planned and replace with 18mm ply then tile
2) tile directly over the top of the floorboards
3) take up floorboards and joists and replace with ...what ? kingspan insulation ? but that will flex as well.