Customer has PLY thickness issues!

[bobbin]

Turning into a problem this, I have a customer who wants there kitchen (open plan) to be tiled. This a new extension and the dinning room has been laid with oak floor so the tiles need to meet up to it!
The kitchen has a chipboard floor screwed into floor joists, so this leaves about a 20mm drop from the edge of the oak floor.
The problem is I think the floor will need to be plyed with 18mm to ensure it doesn't flex in the future, the kitchen is about 9m square. So with the tiles on top (600 square porcelain) this brings the kitchen floor a lot higher than the oak floor, there's the problem

What would you guys do?

Do you ever get this when doing a quote and you explain that you will need to ply the existing floor and raise it 18mm before you even lay a tile to ensure the tiles stay where you put them?
There is always a problem of either meeting a carpet, or the door won't open due to the height etc.

Help as always is much appreciated

[charlie1]

Ask Darren from NETT, he knows about a ply substatute that is a lot thiner than ply (4 mm) i think.

Good luck.

[bobbin]

4mm, that can't be strong enough to prevent flex can it? if it can it must be silly priced!
Cheers for the advice though mate.

[grumpygrouter]

Ask Darren from NETT, he knows about a ply substatute that is a lot thiner than ply (4 mm) i think.

Good luck.

You will be talking about "No More Ply". Said by the rep on here to be a full strength substitute for 18mm ply but as yet we have seen no written evidence that it does so, only what has been written in marketing literature.

It may be better to use 12mm ply and use the likes of Fastflex or Ardex-flex 7001. Schluter also do a very good "movable" transition which will help reduce the "step" to a slope.

[bobbin]

Cheers guys, it's a pain most of the time! Have you tiled straight onto chipboard before, after screwing in and priming, I have done it my own shower room as a test about two years ago and not a single problem. I wonder if all this 18mm ply is just a bit over kill sometimes. I mean if you screw enough turbo gold screws into the chipboard, the only way it will move is if the house falls down!

[tkm18]

Cheers guys, it's a pain most of the time! Have you tiled straight onto chipboard before, after screwing in and priming, I have done it my own shower room as a test about two years ago and not a single problem. I wonder if all this 18mm ply is just a bit over kill sometimes. I mean if you screw enough turbo gold screws into the chipboard, the only way it will move is if the house falls down!

Im of the same opinion, but BS's are 18m so some folk like to stick with that.

[NickH]

Ive used No More Ply several times and it does the job, 6mm thick and easy to use, avoids a lot of hieght issues.
Home
I get it from Tile depot at about 10 quid a sheet trade.

[grumpygrouter]

Im of the same opinion, but BS's are 18m so some folk like to stick with that.

This BS is for situations for strengthening a floor, not just "if it is chipboard it needs to be over boarded" per se.

The main issue with chipboard is the fact that it can be very unstable with moisture. Ply is also unstable with moisture but less so.

If a floor meets BS for deflection then there is no real need to overboard with 18mm ply as it does nothing but add cost and give a step to deal with. If on the other hand the there is issues with the chipboard getting wet, then you have another issue entirely. There are adhesives that have been developed to cater for tiling straight onto chipboard and other timber based substrates (i am not talking floating floors here) and can rightly be used if conditions are right. Some guys on here will not do it and some will. it is down to the guy on the ground at the time to make a judgement call as to which way to go.

These are my own opinions and NOT necessarily that of this forum, I may add.

[tkm18]

This BS is for situations for strengthening a floor, not just "if it is chipboard it needs to be over boarded" per se.

The main issue with chipboard is the fact that it can be very unstable with moisture. Ply is also unstable with moisture but less so.

If a floor meets BS for deflection then there is no real need to overboard with 18mm ply as it does nothing but add cost and give a step to deal with. If on the other hand the there is issues with the chipboard getting wet, then you have another issue entirely. There are adhesives that have been developed to cater for tiling straight onto chipboard and other timber based substrates (i am not talking floating floors here) and can rightly be used if conditions are right. Some guys on here will not do it and some will. it is down to the guy on the ground at the time to make a judgement call as to which way to go.

These are my own opinions and NOT necessarily that of this forum, I may add.

I was talking generaly, not just about chipboard.

With experience you can generally judge what is needed when tiling a wooden floor, sometime nothing, sometimes just tightening up, sometimes overboarding.

[CJ]

12mm hardibacker glued and screwed........leaving (If I read it right) 8mm for tile.......if 10mm tile.......are they gonna moan at 2mm height diff ?

[GazTech]

Im of the same opinion, but BS's are 18mm so some folk like to stick with that.

Hi mate BS's are 15mm, if you need to pinch 3mm, then lay 9mm then 6mm ply.....Gaz

[tkm18]

Hi mate BS's are 15mm, if you need to pinch 3mm, then lay 9mm then 6mm ply.....Gaz

I thought they were 18m, even 15m is excessive in my opinion.

But who am i to argue?

[Dave]

12mm ply and Fastflex........

[andy-p]

dave if the substrate was solid what would be wrong with 6mm ply or backerboard and 2 part ??

[grumpygrouter]

dave if the substrate was solid what would be wrong with 6mm ply or backerboard and 2 part ??

before Dave replies, I refer back to my previous post....if it is solid, why overboard at all?

[GazTech]

If substrate is sound why overlay at all with fastflex ??

[GazTech]

SNAP Russ....lol

[Dave]

I said 12mm just to bring the floor and tile up to the wood floor height..that is all.....YES!! you can tile straight on to it..but the question was regarding the wood floor height issue wasn't it..?..

[GazTech]

Aye...sidetracked again....lol

[DS Tiling]

I wouldn't take the risk of putting 600x600 porcelain direct onto chipboard even with fastflex. 12mm+ ply or backerboard equivalent at least and with a modified grout and an oak threshold strip. Your trowel notch size is goig to raise it as well.

[bobbin]

Thanks for all your reply's people, much appreciated. This nomoreply appears to be another type of hardibacke, just thinner, again to help stop the moisture content entering the chipboard. I will speak to my tile company and see what they sughgest and explain the views I have got from you guys and go from there. I'll let you know what I go with.

[silver]

Hi, I would suggest the hardibacker board too...top stuff and starts at 6mm.....as with the chipboard and tiling onto it...adhesives will stick to it but I find its the top fibres that break down and away from the rest of the board with moisture....not the adhesive failing If its an area that aint too big.....you can tank chipboard, it will adhere....that way no moisture will reach the board and create the "breakdown" of the fibres. Its supposed to be a no no to tile onto chipboard, however, a recent chip shop floor took me ages to get the *kin tiles off it !

[devonmark]

I use 'no-more ply' all the time, hardly ever use ply now, it comes in 1200mm x 600mm sheets and costs £7 a sheet trade from tile giant.

[smurf21]

re-screw chipboard 6mm marine ply fastflex adhesive large format trowel gives you your 20 mm and if you put enough screws in and stagger the joints it should be fine but you have to make the call your doing the job. but if the floor flexes on the joists then you have to stick to your guns with 18mm or dont guarantee the job.