The right screws please Grommit!

[STEVEROG]

Another post for you seasoned tilers....

Whats the right screw type and size to use to fix my 18mm plywood down onto bare joist floor.

Steve

[cornish_crofter]

I usually use bog standard 2 inch posidrive to screw floorboards down, they've always been good enough. I've never had the need to screw ply down for tiling.

Some may suggest brass or other material resistant to corrosion.

[grumpygrouter]

You will need corrosion resisant screws as the addy not only contains moisture but also the chemicals are corrosive too in their uncured state. As a tip, I was also taught that it is better to pre drill your boards to the shank thickness of the screw. You are then "clamping" the board and it is then less likely to lift when you screw it down, eliminating potential voids.

[Dave]

Brass or stainless....

[STEVEROG]

Thanks gents. From the information supplied I think I will go for 2 inch stainless into pre-drilled and countersunk holes. I think the stainless is probably better than brass as I guess it will take a lot more torque so I can really wind the boards down tight.