Bathroom floor reboarding query

[skhudy]

Hi bathroom floor I did a patch up job with knackered joists a decade ago but redoing it properly this time.

I've properly straightened / strengthed / sisters the joists after taking up the floor

The question is should just put the 18mm ply iv bought on top, or relay the floorboards and then the 18mm ply on that.

Thanks

 

[bobasd]

screw ply straight to joists.

 

[skhudy]

screw ply straight to joists.

great thanks for clarifying

 

[opps]

And then DitraMat over the top of the ply?

https://www.tilefixdirect.com/blog/2013/04/benefits-of-ditra-matting/