marine ply

[terrycoe1]

hi all i have a job to tile at the weekend i popped round the other night to have a look what needs doing basically its 2 walls one being 2000 x2000 and 2000 x1000 the owner has put up marine ply as its a conversion shower base is in etc hes left a 2mm gap between marine ply for movment its fixed well im intending on waterproofing and priming before tiling onto it also using bal white star addy its the priming overkill tho or should i just water proof boards and joints ?? thanks

[Dave]

IMO... The ply is not suitable...

What tiles are you using.?

[Phil Hobson]

White star, is that not tubbed adhesive?

[timeless john]

If your expecting 2mm movement in the plywood that has to tell you something about the suitability of the construction!
Use the plywood as the background to overboard with a waterproof tile backer board and get all the edges tanked.
Good Luck and have fun.

[terrycoe1]

i have tile onto this before and was fine but was only a small area half the size using white star too obs bigger area i shud use a flex addy ? its firmly fixed theres no bounce or flex in the marine ply he has put up but i wasnt 100 percent i was just goin by what i originally done in a previous job primed and waterproofed and sealed joints etc but like i say was half the size this is twice now were i have had this and its due to the plumber saying to use marine ply :-?im thinkin board over it??then tile the tiles are light weight nothing special 200 x300 i think ?

[terrycoe1]

rung bal technical today and asked about tiling onto marine ply and told the what tiles and wat the job is they have told me its ok to use the bal white star its highly flexible and just prime and water proof the ply seal the jonits etc question answerd :-)

[Rich]

Ply is not suitable for a wet area. I would want the ply removed and replaced with a suitable substrate and then I would want the plumber hung.

If you go ahead and tile this then just cover your self and use a powder adhesive, I would even go for a 2-part S2. Forget about the tub, regardless of what BAL say.

[trevortine]

When you say marine ply do you mean proper marine ply or are you confusing it with wbp ply, there is a big difference, not that i would use either in aforementioned application. Just curious!

[terrycoe1]

its propper marine ply what they use on boats he payed a lot of money thats for sure for it i did say why didnt you use hardi or somthing like that but because of what the plumber said he went ahead with this taking it down or evan boarding over it is out of the question as hes payed alot o money like i said for it and he isnt willing to do that so i have to go ahead with the job so i needed a solution to get round it i defoo wouldnt use any wood based backing boards thats for sure if i was putting it up but need an answer to overcome this :-S i think i will go for a powder addy and still water proof and prime the boards if rung tech and covered my self in everyway that way

[trevortine]

Was gonna say apart from the different types of wood used to make it the price is a big factor too! More than double of wbp!! How thick is it?

[deanotile]

BS5385*The use of sheets and boards that are subject to movementfrom changes in moisture content, e.g. wood-based materials such as plywood,chipboard, wood particle boards, etc. should be avoidedif at all possible. If such boards have to be used they should berestricted to small areas and tiles should not bridge joints between boards. Itis good practice to seal all exposed edges and the backs, but not the faces, ofsuch boards with a suitable sealer to prevent distortion by atmospherichumidity changes. Care should be taken to ensure such boards are not installedin a condition where their moisture content is higher than the ambientequilibrium moisture content once the tiled installation is in use. Failure toobserve this can lead to subsequent warping and distortion of the boards withconsequent cracking and delamination of the tiling. *

[terrycoe1]

there thick maybe 12mm or so ?

[Dave]

I understand you have to tile it as it is now but please do not used a tubbed adhesive..

IMO Keraquick with latex plus or Weber rapid set plus with AD230..after you have tanked..

[kopthis]

I use plasterboard and tank it, no problems have ever come back to me Iknow as have done this to friends houses over the years and there has been no complaints and we are still friends

[terrycoe1]

i think its one of them things were some say its ok and some say no i have been tiling for a year now so only reli finding my feet ! check out some of the work i have done on my page be much apreciated for comments! :-) to see how im doing! lol i shall buy a powder addy high flex and shall tank the walls

[terrycoe1]

kopthis did u mean u use ply as u put plasterboard ??

[kopthis]

no i use plasterboard tank and tape it all no problems and only use powder addy,once tanked you can use he shower even before you tile it and the plasterboard stays dry as a bone

[jay]

Tubbed adh is not suitable for tanking

[pjc]

if you cant get them to change it you might get away with liquid tanking but its not the best way ask the customer they know best lol they dont really need you do they ?

[terrycoe1]

hmm well jobs tomorroo! i shall let u all no how its goes he deffo wont change the board so im goin to have to tank it and prime it and make sure that there well secure wich it was when i went to the job not a single bit of movment ill tape up edges etc too

[pjc]

he has sealed the back and edges ? as he knows al about tiling

[Rich]

If you have only been in the game for a year then you are learning one of the biggest lessons to learn... Builders/plumbers and any other trade know NOTHING about tiling but they all think they know everything. It is a constant battle for all of us with morons who think they know what they are on about.

Best of luck with it, I would make a point of telling the customer and the plumber that it is completely wrong ( be ready to hear "Iv done it loads of times and never had a problem") and tell them to call you sooner next time so that you can give the right advice at the beginning, do the job correctly and probably save the customer some money.

[terrycoe1]

i have since spoke to the customer xplained what should have been put up etc basically i have coverd my self in every posible way ! :-) ill do a great job tiling and do everything that i can possibly do to make it job safe ! it is frustrating as this is what courses stress! hah! and yes is a constant battle thats for sure! he prob hasnt sealed back edges but thats why im planning to taper up all corners etc well and seal

[Rich]

It seems that you have done all you can. Just one more thing, are you planning to prime the ply before tanking? Or prime the tanking before tiling?

The only reason that I ask is that a lot of brands do not recommend priming after tanking and others do not recommend priming the face of the ply, only the back and sides (this is to reduce the risk of warping from moisture from behind the boards).

Would be worth checking with the manufacturer of the adhesive and tanking kit

[ian158]

I recently retiled a shower area, the plaster board had been up since 1984, and it was only damp behind, at the bottom because the silicone had split, are we not over killing by using all these water proof boards, if there is a good seal, why not use plasterboard ?, in 15 years time, when you dont have to worry about the guarantee, the owners will probably want to up date anyway, all these new backer boards, are they really necessary. ?

[paul damian]

as above , builders are not tilers, they will drop you in it faster than a falcon in freefall. If tiles fail its the tilers fault, GET IT.

[Phil Hobson]

Tiles/ grout are not waterproof, so a backerboard will allow water ingress, but not break down as plasterboard will, just my take on it

[Rich]

Phil has hit the nail on the head... Yes, they are completely necessary.

[jay]

I recently retiled a shower area, the plaster board had been up since 1984, and it was only damp behind, at the bottom because the silicone had split, are we not over killing by using all these water proof boards, if there is a good seal, why not use plasterboard ?, in 15 years time, when you dont have to worry about the guarantee, the owners will probably want to up date anyway, all these new backer boards, are they really necessary. ?

and how does the plaster dry out/// waterproofing has its place and in my opinion is a wise move ,if its done right we should see no more ceilings with water damage (due to upstairs bathroom) or rotting timber and carpet in the next room .

[terrycoe1]

when i rung bal tech i had asked wether to prime they said yes it comes with the kit i primed then tanked dryed of nicely and the marine ply is 24 mm + thick !! it feels solid too i sealed all edges as well