Plywood needed for laying ceramic floor over...

[spada01]

I've looked on the web and found lots of conflicting information such as 9mm ply, 18mm ply, marine grade, no need to use marine grade.

It's for a kitchen, to go over floorboards and realistically I can't see that marine grade is needed and regarding thickness requiredto prevent tile cracking I would just go for 18mm to be safe, but thiswould leave a sizeable 2cm+ ledge between teh kitchen floor and hall carpet.

So... what thickness ply do I need and indeed would a professional use?

 

[Richard C]

Your right that you don’t need marine grade ply, WBP will work just as well. It's similarly constructed but doesn’t look so nice but as you’re covering it up anyway, it doesn’t matter. IMO overboading requires minimum 12mm but some will say you need 15mm (which you can’t get) so it’s up to 18mm; others will say you can get away with 6mm but don’t believe them. IMO replacement boarding requires a minimum of 18mm - 25mm, depending on local circumstances. I prefer to replace as I can be sure of the base & it avoids a huge threshold step. Then there is the all important choice of materials to use.

There are many personalised opinions on what's best to do, read the Forum tiling sticky, read back through the archive posts on the tiling forum & make your choice depending on your personal circumstances & budget but, remember, a kitchen is a heavily utilised area.

 

[hotrod]

No need to use marine ply that's way ott (I could tell you an story about an experiment WS Atkins did at a naval college where they left marine ply submerged in a tank for 18 months - but I'd probably bore you).

If you're having problems marrying up floor levels consider ripping up the existing sub-floor (I assume it's 18mm T+G) and use either 18mm or 25mm WBP Ply (which ever thickness works to level best).

EDIT: Post crossed with Rich's. Didn't nick his ideas honest guv

Alreet Rich, great minds eh

 

[Richard C]

EDIT: Post crossed with Rich's. Didn't nick his ideas honest guv

Alreet Rich, great minds eh

No problem

 

[spada01]

Thanks guys - unfortunately it's not T&C but floorboards from 1890 :-O I'm changing the floor around an existing kitchen so taking up the floorboards isn't really an option. From your posts I'll go with 18mm ply. Any ideas on the step or is this something that I'm going to be stuck with? I was thikning about removing the floorboards for say 30cm from teh door and tapering down to teh door leve, but this has teh potential to look very naff!

 

[Richard C]

Any ideas on the step or is this something that I'm going to be stuck with?

Yes.

I was thikning about removing the floorboards for say 30cm from teh door and tapering down to teh door leve, but this has teh potential to look very naff!

IMO very naff. Best method is to make a hardwood threshold using the timber of your choice.

 

[spada01]

Any ideas on the step or is this something that I'm going to be stuck with?

Yes.

I was thikning about removing the floorboards for say 30cm from teh door and tapering down to teh door leve, but this has teh potential to look very naff!

IMO very naff. Best method is to make a hardwood threshold using the timber of your choice.

I like your wooden threshold idea a lot and will go for this - thanks Richard!

 

[spada01]

Last query...When you screw the ly to the floorboards d you ork out where the pipes run and avoid these areas or do you use screws that ren't long enough to reach them?

 

[alittlerespect]

Hi

Go to a local joinery shop (if they still exist) and ask them to turn you out a tapered hardwood threshold plate, make it the same width as the door lining and it won't look too out of place. Also the threshold plate will warn people of a change between floors - rather than having a 'trip hazard' to contend with!

Regards

 

[Richard C]

Last query...When you screw the ply to the floorboards d you work out where the pipes run and avoid these areas or do you use screws that aren't long enough to reach them?

It’s very important you locate any pipes & cables before you start screwing the ply down. You should also establish the joist layout & it’s usually easier & more accurate to lift a couple of floorboards temporarily to do this.

When over boarding, I always screw through the floorboards & into the joists, don’t just rely on fixing into the top of the floorboards. Fix every 200mm & position any joins in the ply over the centre line of a joist.