Screws for plywood

[Jupiter01]

I am planning to fix 5.5mm plugboard over my floor boards before I lay vinyl flooring into this.
I wanted advice on the type of screws I should use to ensure they don’t harm the flooring and secure the boards appropriately.

 

[SFK]

Lots here,
https://www.screwfix.com/c/screws-n...agedredirect-_-screwsfixings-_-flooringscrews

For heavy duty ply (in Bathroom) I use these:
https://www.screwfix.com/p/spax-tx-countersunk-wirox-flooring-screw-4-5-x-60mm-300-pack/88716

 

[Jupiter01]

Thanks @SFK
I have used the floortite screws in the past but aren’t they all too long in this situation. My ply is 5.5mm and I then just have the floorboards below that (unless I a lucky to hit a joist). Or have I got this wrong and should only be screwing where I have a joist?

 

[SFK]

For 5.5mm ply which I presume you are simply using to provide a bonding surface, I would only screw into floorbards.
Simply because risk of hitting something else (pipes and wires), and difficulty of finding joists under the boards, I would use 4mm x 25mm screws.

If on budget these:
https://www.screwfix.com/p/goldscre...k-multipurpose-screws-4-x-25mm-200-pack/17430

These are sharper and faster to get in:
https://www.screwfix.com/p/turbogol...k-multipurpose-screws-4-x-25mm-200-pack/15732


Note that they will all harm the flooring. If you mean the vinyl, countersink and pit a bit of wood filler over screw.
SFK

 

[dazlight]

Or use ring shank nails 19mm