can feel an arguement coming

[grahamster]

hi guys, need to get armed with ammunition,just priced a kitchen floor,30m2.Told the customer to use 12mm ply blah blah,customer phoned joiner who in turn said 6mm ply will do,which i dont think is right,i know 6mm backer board is ok,but 12mm ply is the cheaper option,can you please give me some advice/ info so i can reply........cheers Graham.

[Dave]

Who's the tiler here...?....tell the joiner to stick to what he knows and leave the tiling to you........just tell the customer its 12mm or nothing..get someone else....or tell them to come on here and we will tell them what is required...........

[grahamster]

Thanks dave,but what im wanting to know is why not 6mm ply,i remember coming away from course last year,drummed into me that it was 12mm,& i have been quite lucky on the floors i have done that i have persuaded customer to use 6mm backer board,but i cant remeber why we dont use 6mm ply.......cheers Graham

[grumpygrouter]

Why don't you ask the joiner to give you some info on what adhesive and grout you should be using too, maybe even recommned the tiles and what size groutline is appropriate. He seems to know what's required, better still do as Dave says, get him on here and we can "point him in the right direction".

Stand you ground Graham, you are correct! 6mm ply? you might as well put lino down!

Grumpy
----

Originally Posted by grahamster

Thanks dave,but what im wanting to know is why not 6mm ply,i remember coming away from course last year,drummed into me that it was 12mm,& i have been quite lucky on the floors i have done that i have persuaded customer to use 6mm backer board,but i cant remeber why we dont use 6mm ply.......cheers Graham

6mm ply isn't rigid enough to stabilise the floor. It is too easy to screw it down and leave voids underneath.

grumpy

[Dave]

6mm ply and 6mm backerboard...totaly different materials mate....the 6mm ply isn't stable enough to strengthen the floor..and the 6mm backerboards are stuck down with adhesive and then screwed as well.... much stronger than 6mm ply alone....12mm ply will be cheaper option...make sure the orignal substrate is well fixed as well.....

[LM Ceramics]

to be honest i have only plyed small bathroom floors before and ive used 6mm plywood before ive not had any trouble with it

[grumpygrouter]

Originally Posted by LM Ceramics

to be honest i have only plyed small bathroom floors before and ive used 6mm plywood before ive not had any trouble with it

What was the reason you ply'ed out the floor? Just because it was chipboard or because it had movement?

Grumpy

[Woody123]

i agree with all of the comments mate. I would only use 12mm (min) ply with 2 part flexi adhesive. British Standards is 18mm ply but most think this is overkill. 6mm ply is just not structually stable. You could tell the customer that if you used 6mm ply the floor will flex as it wont have enough stability in it resulting in tiles possibly coming loose and grout cracking. If the customer still insists on this then i would either walk away or tell them that you will not guarentee any of your work against failure as correct procedures haven't been followed! Hope this helps
Chris

[grahamster]

Ok thanks for all the comments,feel a bit more relieved now,at least i can tell customer something......cheers Graham.......and the joiner!!

[Fekin]

I think it's a case of certain methods should be followed like not using just 6mm ply, but there will always be pleanty of people who use 6mm and don't have problems with it.
There again there will also be many that do have problems.

I guess it comes down to the customer too.
If they have had the floor done with 6mm, and 3 or 4 years down the line tiles start cracking or lifting, the customer might think well it might be time to have it done again, and not try and find the tiler who did it 3 or 4 years ago, where as someone using stronger or thicker boards might never fail or 10 years down the line.

Just like we have with PVA.

[dptiling]

Originally Posted by LM Ceramics

to be honest i have only plyed small bathroom floors before and ive used 6mm plywood before ive not had any trouble with it

same here small areas, but tons of screws.
only because of height . with 12 mm
but have made a fuss of it .no movement before tiling.
never had any probs.

(when you think they addvertise addhesive to go stright on to tounge and grove floor boards) with no ply at all ...

[Fekin]

Originally Posted by dptiling

(when you think they addvertise addhesive to go stright on to tounge and grove floor boards) with no ply at all ...

Like fastflex, but that has a very high flexi rate anyway to allow for more movement.