Jobdone! - Tile Advice

[Chris1397]

Hi there, I do joinery, landscaping, decorating, roofing, plastering, concrete casting etc etc. Inevitably some of my customers ask me to tile! I hate tilling! its a minefield! hoping for some professional help in the near future.

 

[Old Mod]

Hi and welcome to the forum Chris!
Well, we try!

 

[Chris1397]

I framed out a 3 sided walk in shower, insulated it with 100mm celotex, lined the area with 12mm marine ply, primed the ply with weber primer 360, i used a unibond readymix bathroom tile adhesive, 150x150x5 basic white tiles from B+Q (i buttered every tile) then grouted the lot with Mapei Flexible wall and floor grout for kitchens and bathrooms.

8 months on i saw i little movement on 1 tile and decided to investigate!

i pulled the first tile off and there was thick black mold behind it, which lead to the next tile and the next etc, ive had to remove the bottom 7 rows on all 3 sides because of this black mould. even the ply was soaking wet ive removed that too.

the plan is to dwang the joins and patch in with new marine ply after that im stumped! i dont want this happening again!

Where did i go wrong?
Dont use ply?
Dont use a readymix adhesive?
Are B+Q's tiles so cheap they are porous?
Was the grout to blame?
Should i have primed the tiles?

Any help with this matter would be greatly appreciated.

Read more: Tiles falling off inside new shower cubicle.

 

[Old Mod]

Honestly?
Strip it all out back to frame.
More noggins.
Board with 12mm Hardibacker or tile backer board.
Stagger joints.
Tape joints.
Tape between shower tray and wall.
Use shower tanking kit like Ardex WPC.
Tile using bagged tile adhesive not ready mixed.
Grout
Silicone
Leave for 7-10 days
Shower
Jobdone!
It'll save u time and grief in future, to just start again.
Put it down to experience and never use ply or tubbed again.
That's what I would do.

 

[White Room]

What he said

 

[Chris1397]

Thank you for the warm welcome and wise words 3 fall. I guess thats what i thought you might say! You say dont use the shower for 7 to 10 days? Im thinking back and last time i grouted i only left it overnight before using the shower in the morning! what consequences could there be from doing that? oops!
Ive cut out everything to head height, all seems stable, dry and mould free above! ill stick some noggins in and patch everything below with hardibacker, and whack some Ardex on. I hope i can find that or something similar tomorrow at TP, Jewsons or B+Q? Yikes the wife is going crazy i need to get a move on with this! wait till i tell her she has to let the grout dry for 7 days! lol

 

[Old Mod]

Haha it's not just the grout, it's best to let everything cure properly before using that's all.
Drying time is not necessarily curing time.
There's numerous tanking kits out there, all fairly similar.
I mentioned the Ardex cos I believe it's the easiest to use for diy.
Because of its colour it's difficult to miss bits out.
Others are very pale and patches can easily be missed, especially against similar colour backgrounds.
Well the last thing u wanna do is rush it isn't it, we already know where that leads! Haha
Let her read the posts, I'm sure she'll understand!

Coooee Mrs Chris!

 

[Chris1397]

Many thanks 3 Fall. im going to do a proper job this time.

 

[Italy]

attentive @Chris1397
@3_fall . over counseling. asks for money
welcome to tf

 

[Stevev]

so....to be clear, the real reason for the fail here sounds like Chris used the shower and got the grout/adhesive wet much too soon, so must have exposed a gap???

 

[Old Mod]

so....to be clear, the real reason for the fail here sounds like Chris used the shower and got the grout/adhesive wet much too soon, so must have exposed a gap???

No haha I wouldn't say that tbh, it may have been a cintributing factor, but not the cause.
The cause was simply a bad install, start to finish.

 

[Stef]

I've ripped out a lot of showers where ply has been used & they were all the same, black mould everywhere.
Wood & water don't mix.
You would have been better using standard plasterboard & tanking that.
I would use wedi or marmox boards (there's plenty more out there) & as they are waterproof then it's only the joins that need taped & you won't have a bit of bother.
I use Mapei Aquadefence for waterproofing showers before I tile & it's very easy to use.

 

[John Benton]

This is what happens when you use ply in a shower

 

[Andy Allen]

Welcome Jack...

 

[Chris1397]

Sorry folks ive been busy. Ok so there are probably many contributing factors as to why it went wrong in 8 months. Having said that i did prime the ply i did butter every tile meticulously, let the adhesive dry for 24 hrs as it advised, i squeezed and worked the grout very carefully into all the joints and sponged off leaving perfectly even grout line and let it dry for 24 hrs as is advised, i thought i had done good! it looked perfect. i still cant believe it failed so quickly.
I have now cut out all the ply up to head height on 3 sides, dwanged and fitted hardibacker, primed, taped joins, twice tanked, and laid new tiles on 100% bed. BUT im still nervous as on closer inspection the cheap B+Q tiles have varying amounts of glazed cover on the edge of the tiles varying from 0.5mm - 2mm! Secondly, i just noticed the bagged adhesive i purchased at B+Q was 3 month past its use by date. Thirdly, because im patching in i am held to the previous pattern and spacer size but i have noticed on the tile box it says "only use spacers of 3mm and >" i however had to use 2mm to match the existing! does that mean the grout dries to quick and loses integrity? should i seal/prime the open grout lines before grouting to slow the suction rate? I hate tiling......