Big bit of ply, or cut into smaller bits?

[Bladd]

Hi

I am redoing our bathroom. I'm going to be laying 18mm plywood on the joists (16in centres, with noggins) and tiling on that using a decoupling membrane (Ditra 25). My plywood is 2440x 1220mm.

Is it better to lay the plywood in one big sheet or cut it into smaller sheets with 3mm gap between them?

I'm thinking about potential expansion issues. The 3mm gap between smaller sheets will act as a break for expansion.

Thanks

 

[Ben-gee]

I’d stick to big sheets with gap at perimeters, better for rigidity.

 

[TSCTILING]

Probably done it by now. I never recommend ply to receive tiles. Jackoboard or cement board would be my choice. And definitely fix in 1 piece if possible

 

[Jon_Hall]

I agree with the above, the less joints the better. according to British Standards you will need to over board the floor with a suitable tile backer board, this should also alleviate the need for de coupling.