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Buttering the tile will work.

Why not gripfill............it may work, but I have always used silicone. Sounds bad, but if the situation fits! Your situation doesn't fit as you have all the tools there and adhesive.

I just think it might be a bit of a nightmare, but I've never done it before so just planning ahead. Rightly or wrongly I am planning to bond the edging strip to the wall first to give me an area to infill with the tiles. I will certainly attempt to use adhesive first. If I fail I will have a go with silicone.

Thanks for the help!!

AHH! I've just realised I didn't buy flexible adhesive for the floor tiles! ! Is this really a big issue give I've lined the floor with ply to allow for flex? What is likely to happen down the line?

It's hard to say as it could be fine or if there is a lot of movement then the tiles will debond.

Can I ask, was it 4mm ply you used on the floor?

No slightly thicker. 6mm I think. Could have been 8. I only suggested 4mm earlier to keep the thickness of the wall Tile to a minimum to fit and edging strip.

15mm ply is the minimum.

Flexible adhesive will not cope with more than a fraction of flex in the floor. The grout lines and or the tiles will crack.

get an additive for the adhesive.


Ply does not ''allow'' for flex. It is merely a suitable tiling substrate over joists that have been strengthened.

Well I've plyed over 22mm t+g. Is Not just 6mm ply over joists lol

I use 15mm min over floorboards. 25mm direct to joists.

Check your adhesive as I know BAL require a special one for tiling onto ply less than 15mm thick. Fast Flex, I think it is called. Don't use BAL very often but one of our tilers does.

If the flex was brought within tolerances, then you could have kept the floor level down by using No More Ply (some people have issues apparently, although I never have and have never found problems on the www web) or using Ditra.

rossbarclay wrote:Well I've plyed over 22mm t+g. Is Not just 6mm ply over joists lol

I didn't think for one minute you did as that would be crazy, however 6mm ply is unsuitable to tile on to anyway regardless of what it's been placed on top of. You might get away with a small bit of boxing but for a floor I wouldn't have used it.

There is a reason BS states 15mm ply as minimum when over boarding

Did you at least prime the back of the ply before laying it down?

No, I asked contractors that were in doing some work in work amd they both advised just to line with 6mm ply, no need to primer etc providing the floor underneather was is sound condition. The hardware store where I bought the ply also said that tilers were in all the tile buying 6mm for jobs all the time ( I challenged the quality of their board as I was told something abotu middle east and far east board and one of them being sub standard). I had asked for flex adhesive but it seems the wrong one was laoded when I bought it and I've only relasied after I've completed the jon.

What is the reason for 15mm ply board and the reason to prime the back of the board?

What should I do when tiling the shower cubicle as I want to make sure I do thsi correctly?

Funny I jsut bumped into one of them still working on site here. He said that the 6mm is fine as all I am doing is giving the tilie a base which does expand and contact i.e plyboard does not. He said the floor undeather maywell move but the ply wont? Does that sound right?

The reason for priming the back is to offer addition moisture resistance from humidity. Have you ever seen wooden worktops cup and bow? This is when the face is oiled and the underside left bareand humidity attacks the wood from one direction. The same happens to ply or any timber for that matter.

The reason for 15mm minimum is so that the ply offers its own support and can bridge any voids underneath it. In addition it is not as prone to warping from small amounts of moisture and humidity, just the water content in the tile adhesive alone is enough to warp and delaminate the ply.

Many people use 6mm ply because they know no better, especially builders who don't understand tiling. It is not guaranteed that your floor will fail because you used 6mm but you have added another risk that it could.

Some ply on the market is of poor quality as you have heard so this again has its own problems as the resin used to bind the layers is poor. It's the reason a lot of people are turning there backs on ply and using tile backer boards instead as they do not have the same issues as timber products and are much more dimensionally stable.

rossbarclay wrote:Funny I jsut bumped into one of them still working on site here. He said that the 6mm is fine as all I am doing is giving the tilie a base which does expand and contact i.e plyboard does not. He said the floor undeather maywell move but the ply wont? Does that sound right?

Educate him then.

Ply will expand and contract, all timber products do. Ply is more dimensionally stable compared to a straight piece of timber but it will still expand and contract. Again that is why you should leave a small expansion gap between each sheet that you lay.

Ask him if engineered flooring expands and contracts? That again is another product which is ply based.

Unfortunately there are tilers and there are tilers.

Take many tilers, who are self taught, done 6 months with a tiler, sought knowledge off the net (which has some shocking knowledge that can be taken as correct). They use improper adhesives, substrates. Can only tile to an extent and certainly couldn't do an envelope for a bespoke tray.

Take the ones we use (normally one now) when I am too busy to do the tiling, all time served as a minimum. The one we mainly use now is time served and had to attend college for 2 years, during that time. They have the correct knowledge and skills to throw up contract tiles from ceiling down to the floor, floor up to the ceiling, envelope work, book matched work etc etc and all in a quick time.

All you hear in the shop is that all these tilers say 'blah blah'. They could all be ill trained house bashers or were sitting behind a desk 3 months ago before being made redundant!

You need Far Eastern Ply and from a reputable source. Travis Perkins would be a good bet to mention because they are a national company. Quality product which will not delaminate, you pay a bit more. But still cheap compared to paying less for an inferior product that will cause problems.

Why 15mm minimum. Your floorboards will not be dead flat. Thinner ply can sink into the cups of the boards over time and this will cause bond failure and could crack the tiles. Even tile backer board needs to be bedded on adhesive to remove these voids, otherwise the same scenario could occur.


Shower cubicle...........

Put batten around the walls to support the tray, even if it has legs.
Slide tray into position, mark around the top in pencil.
Pull tray back out and then apply silicone between the batten and pencil line.
Push tray back in and remove excess silicone.
Let it go off for 24 hours.
Do the tiling and leave internal corners grout fee and around the bottom tiles and tray.

Follow manufacturers instructions for fitting enclosure. Pay attention to exactly how they say to apply silicone. They all vary! Grout around tray and internal corners at the same time. Internal corners first.

You obviously have to plumb the waste in at some point too.

Plywood does expand and contract....what a wnker, telling you it doesn't!! Even tiles will expand and contract.

Does your floor have any deflection? i.e bounce? Again 6mm ply would offer nothing in the way of strengthening.

Tiling isn't as simple as sticking square things to ways, if you want it to last then the prep is important as with any trade.