Hello I am new to this site and I joined with the hope that someone will be able to give me some good advice?
I have recently had a loft extension with an en-suite. In the en-suite i have a shower cubicle which is tiled with flexible adhesive and grout straight onto ply and I have suffered the grout cracking twice in pretty much the same place from tray to ceiling.Was using ply correct? obviously the loft will suffer from movement is this why it is cracking? I would be very grateful if anyone could offer any suggestions.
Craig

Hi Craig! Try to use flexi grout

TO TF.

Why did you use plywood in a shower area?did you use a water membrane to protect(tank)the ply?

One reason could be that it is on a joint between two pieces of ply but i think the main reason is that the ply is getting wet and expanding and contracting this causing the grout to crack.The grout might ton be drying out at all if the ply is soaking wet.What was the ply fixed to?timber?

The builder put up the ply and i pva sealed it before tiling it.

[QUOTE=brian c;291520]TO TF.

Why did you use plywood in a shower area?did you use a water membrane to protect(tank)the ply?


Always use the membrane in wet room if the walls,floor is are other then cement

pva..well thats a no no for starters.

http://www.tilersforums.co.uk/tile-a...ght=pva+primer

hi craig,there was another post yesterday where tiles had crackes on ply in a showerroom and i have also seen this personally,,really ply has no place in shower areas imo and sounds like brian says that movement/expansion of the ply is breaking your grout mate

Thanks to you both for your input on this matter.
It looks like I have committed the cardinal sin by using both ply and pva.
Would you suggest that the ply is removed and replaced and if so with what?
or can I salvage what I have got ?

In france we use to fix wall tiles in "green placo" (plasterboard water proof) but anyway I apply a primer and then a painting membrane,once dry is like rubber and it work's!
Here we have mapei too but i prefer weber & broutin!

The news you don't want to hear Craig is that it wants starting again but if you can't afford it then you are going to have to limp along regrouting every month or so. Sorry

What would be the best product to secure onto the stud wall if starting again?

Craig as faithhealer says,it will probably need to come out around the shower anyway.I would take it back to the length of the showerscreen and replace with hardiebacker or plasterboard which i would then tank and re-tile.

id use either plasterboard or backer board with a waterproof membrane make sure u screw the plasterboard

can we have a pic?

Try Aqua Mix Grout Colourant. It may work because it is an Epoxy Paint! If it doesn't its cost you 20 Quid to try it. Available off tradetiler.com a forum sponsor or off E Bay on line.

tel

Originally Posted by LM Ceramics

id use either plasterboard or backer board with a waterproof membrane make sure u screw the plasterboard

Something rude springs to mind.

Hello Terry
Thanks for your suggestion would this product fill up the crack and seal it at the the same time?

Have you tried silicone? A couple of photos would be good so we could see the problem a bit easier.

Originally Posted by enduro

Have you tried silicone? A couple of photos would be good so we could see the problem a bit easier.

may be a good idea this a colour matching silicone may work

Unforunately my camera is flat but the cracking is between the tile and the grout and not actually the grout itself if thats any help. Will I put the silicone into the crack or do I have to dig out some grout first?

Dig out the grout first then silicone

everything said seems sensible advice.I like to use a grout additive in place of water if i am going over anything other than concrete

I think you could rake the grout and then either use flexi grout or an adflex in your grout mix
It sounds like there's movement in your studs behind the boards,i have seen plent of tiling done over ply and is still being done

If its the grout cracking in the corner/edges to shower tray and not in the joints - then rubber silicone seal all these.
What thickness plywood was used and was it in full sheets?
As suggest when you can supply some pictures you'll get more comments.
In the worst case scenario if you replaced the walls and retiled your best solution would be onto wedi board - tanking the corners and junctions.
Hope the sealant solves the problem!

if the crack keeps happening in the same place from the base to the ceiling, then this is a movement/structural crack...somewhere along that line there will be a joist or floor issue that is causing the movement that is causing the crack...

did the ends of the ply wood fit fully to the corner of the vertical studwork or was there any overhang? what centers was the ply fixed at 300mm 400m?

theres so many factors with loft conversions that have to be considered...you have a new suspended floor, weight of the roof, lots of new stud work etc etc...as above some pics would help solve this accurately and promptly for you

ed