Prepping Floor boards / No More ply - Tile Advice

[Jimbobble]

Hi,
I've got a kitchen to do next week & am laying 330 x 330 ceramic onto a mixed concrete & wood floor (used to be a chimney breast where the concrete is).
Just a quick question about Cement particle / Marmox / No more ply as I've never laid it before. Will 6mm do and then screw into floorboards after a quick skim with adhesive? I'm going to use 25mm screws after priming floorboards.
I'm assuming the floorboards are 20mm thick at their thinnest so a 25mm screw through a 6mm cement board & a 1 or 2mm skim of adhesive shouldn't be poking through at all should it? I'm probably being overly cautious but am concerned about pipework or wires under the boards! The house was built in the 50's & I know from days working as a builders' labourer that any multitude os sins could be hiding down there.
Any advice would be appreciated here,
Thanks,
J.

 

[GoneGuy]

When I use no more ply on floor boards, I make sure the floorboards are screwed down and secure, sweep the floor then use the mega strength glue on the back of the cement board and screw in 25mm screws then put a bead of mega strength glue along edge and but up next board. Make sure you stagger the joints.
If your to unsure have a look at the video on their website.

 

[Jimbobble]

Hi Andy,
That's great advice mate. I'm more concerned about any issues you've ever had with dodgy plumbing or electrical work under the floorboards? Has this ever been an issue with jobs you've done in the past please?
J

 

[GoneGuy]

No never an issue, I've always used the 25mm screws with 6mm boards.
If your screwing onto ply or a different looking floorboard to the rest just quickly check the thickness of it and use a smaller screw.

 

[Flintstone]

Same, bud when laying it over mixed substrates such as this. It's easier to use tile adhesive under the boards instead of the mega strength. And just screw into the wood area and let the adhesive stick the board to the concrete

 

[Stu Lilley]

No more ply is fantastic we use to use hardi but changed to NMP due to their system being fast track, simple and complete. if you get the chance try their 22mm cement board replacing standard T&G..you wont look back