Screwing ply to floor.

[FreeD]

Hi all

Got a couple of bathroom floors to tile on monday i'm laying down 12mm WBP ply onto old floorboards just wanted to check 5mm expansion around room 2mm between boards...prime underside of ply with SBR and what about screwing 300mm centres but through the board into the joists or only into the floorboards? what type of screws? thanks.

 

[faithhealer]

into floorboard only mate or your luck will run out one day and you'll hit a pipe. I use turbo screws

 

[hillhead]

I was blamed once by customer for putting screw into pipe under ply which i layed in bathroom prior to tiles,plumber told her i done it 2 days after i finished,oh and that i had turned her hot water off in attic !! (some hope! )
Anyway a lot of damage done but i had 12mm ply onto 18mm floor boards and deliberately used 25mm screws to avoid such probs,i proved my innocence easily enough,plumber was one bad *** mother**** !

 

[Gazebo]

If the floorboards are sucured to the joists then you can fix to them, if not then imo you need to fix floorboards first then secure ply to boards after sealing as you have said, i go the extra mile and use screwfix stainless steel screws, probably overkill but dont want the screws to corrode and creat a bouncy floor do we.
Being a plumber i screw into joists knowing where all the pipes and cables are (marking out on the ply areas to avoid etc. But like the others have said if you cant see under every board to check you will be unlucky one day.
Gary:8:

 

[doug boardley]

, jmc;.vcx;m,v]cijmf,.;cpodiujdm clxdosiuhb

 

[Gazebo]

, jmc;.vcx;m,v]cijmf,.;cpodiujdm clxdosiuhb

Clear as mud Doug.:lol:

 

[Rav daniels]

all sounds right to me pal, would use 25mm screws, and stagger the joints of the ply boards,

 

[groucho]

If theres flex in the floorboards you have to scew them down. I think if it can be screwed down then screw it. yes if its chip board flooring its hard to locate the joists. i think they use ring nails a lot of the times. I rather have a few screws in myself. go as close as you can to the nail and screw in should be ok. Failing that let the customer do it if you can. Personly i never use ply I always recommend no more ply.

 

[mike walker]

hello mate you will be better off useing Backerboard instead of ply and fix every 150mm

 

[doug boardley]

Clear as mud Doug.:lol:

no idea what that's all about! wasn't me!