Advice - Water entering drywall behind tiles (Shower)

[NHW]

Hi guys,

Noticed one of my lower tiles in my ensuite shower was very loose the other day, tugged on it slightly and it came straight off the wall which it was attached to, the other tiles next to that one were also quite loose so i took those off also. Seems as though the bottom row of tiles on that side of the wall had this problem but to be sure i took up the tiles directly above them and that area was completely fine (see pic)

So i can only assume that its the general wear and tear of the 'splash zone' considering that the shower has been installed since the house was built approx 15-20 years ago.

at first i was expecting all the tiles needed to be removed and to then have the backing walls changed, but now that I know it is limited to that area would the easiest solution be to:

- remove that area of the wall (just the part where the tiles have been removed)

- replace it with some Knauf Aquapanel (concrete backing board)

- get a tiler in to put the tiles back on (i didnt break any tiles in the process of taking them off)

Any advice on how to best solve this issue is much appreciated

 

[Paul C.]

Sounds about right. If you use Aquapanel, I would recommend tanking it with BAL WP1 or Ardex WPC. Aquapanel is water resistant, not waterproof, so moisture can still travel through the grout and through the board, so the tanking will prevent that.

Another option is to use a fully waterproof board such as Marmox or Wedi, and use a waterproof tape to cover the joints where the boards meet each other and the shower tray, and the internal angles.

 

[NHW]

Hi Paul, thanks for your reply and your advice. hope your ok for me to ask a few further questions.

Am i right to assume that there will need to be a small gap inbetween the bottom of the board and the lip of the shower tray area or should the board sit flush on top of the tray, i couldn't tell if there was originally a gap there as the bottom part of the wall has already eroded away.

I'm also guessing that part of the problem might have been either the grout/sealant/silicone not being very effective, as I dont know how to tile i will be getting in a tiler to do that part. Should I ask him to use a specific type of product? Thanks again mate

 

[Paul C.]

Boards down to the floor screwed to the studs every 300mm (bead of silicone across the bottom where it meets the floor), tray up against them, tape across the joints of the boards and overlapping the tray, tank it if required, tile it, grout it, trim any excess tape from around the shower tray, silicone, done.

Silicone wise, most are pretty much the same. But get one with Microban or another anti bacterial agent to reduce mould build-up over time. (advisable for the grout too). If you have a Topps near you, go for the BAL Micromax 2 and matching silicone. Expensive, but it will outlast us all . You may find it cheaper at any other independent tile shop near you if you have one.

 

[Paul C.]

Nearly forgot to mention, tape the boards around any pipework or your shower valves.

 

[NHW]

Ah thanks for another informative reply mate.

I'm very tempted to go the Marmox route as that seems the more future-proof solution, but realised that most of the stuff you need for this job is bought in bulk lol e.g. very hard to find somewhere where i can just get the 1 board of Marmox, the washers for the marmox usually come in sets of 100 and the tape itself seems to be around £30. If I was to look for someone to do this type of job would it seem feasible for under £100? Thx again

 

[Paul C.]

£100 is probably.......[ummm... whats the word......] Optimistic. The labour alone for doing that would probably be a minimum of £150 (tilers day rate if he can do it in a day), plus the cost of the materials which will depend on the area you are doing........ which is..... how big (sqm)?

 

[NHW]

Oh yeah thats a good point, i dont even know where i got £100 from lol

In that case its probably worth me doing the first part and then just getting a tiler in to literally just reapply the tiles and grout back on once ive got the backing board up. worked out its probably only about £60 in materials overall (Marmox board, washers + tape).

Overall SQm of that area is only about 0.3. Its 60cm x 40cm.

How would you suggest that i cut out that existing part of the wall which is damp? I assume its abit harder because im technically not just ripping out a wall but only wanting to 'cut' out a certain portion of it without disrupting the other tiles etc

Cheers mate

 

[vinn]

What you are calling the wall appears to be plasterboard fixed to studs(?): I can see a rusting "screw" head.
Or is the p/b fixed to a masonry wall?
If this is a stud wall then removing the exposed p/b will leave you floating in mid-air on the right hand side.
The next tile goes under the enclosure frame.
The LH side seems to be fitted into a metal inside corner.
Its difficult to tell how the tile was sitting on the rim of the s/base - I think it was a hard contact with no silicone gap below the tile. Its probably the same all around the s/base rim.
Is the fin at the s/rim part of a one-piece shower tray or a separate metal fin?

If you cleaned up the rim & took more photos of the installation - more suggestions might be available.

 

[NHW]

Hey Vinn, thanks for your reply.

Yes you are right it is plasterboard fixed to studs. the rusting screw is indeed the part which is attached to the middle stud along with the metal hook part which goes under the shower tray and thus gives the contact between the tray and the middle stud.

You are also right in regards to it being floating on the right and also left hand side if i took out that section of the plasterboard, as the next tile is indeed within the enclosure frame. The alternative idea that i had to counteract that would be to:

- Cut the section of the plasterboard out but not all the way to the top of the exposed plasterboard

- go behind the plasterboard and anchor another stud (one left and one right ) using the top and bottom part of the plasterboard and to crossbeam it from the original stud for extra support.

I assume/hope by doing that will then give me the 3 beams which are needed (left, right and center) in order to put up the marmox board?

Sorry i didnt have time to clean up before i took a picture this morning but i guess a closeup shot might show some more info:

Really appreciate the advice given so far

 

[foxhole]

How do you know the limit of the damage without uncovering all the wall. Would not waste my time with a bodge repair, rip it out and replace. A shower panel for £80 would do the job in one go , no tiler required and no risk of leaking.

 

[vinn]

Sliding in a piece of backer board wont do much - you might just as well patch back with an off-cut of plaster board.
In the meantime perhaps cut out the damaged p/b and post a pic of whats behind?
The detailed photo shows what seems to be a shower sealing strip or tape (?) & a separate shower base fin - am i right or wrong?
The way that the silicone has been applied as a remedial measure indicates that there have been previous problems.
Its worth noting that unless the tiles have tiny grout nibs (that space the tiles) then the grout isn't going in further than skin deep.

If i had been called in to attend to such a situation as you have, I would have recommended stripping all the tiles and the enclosure back to bare walls.

Enclosures are sometimes fitted on the outside edge of the tray but your enclosure appears to be overhanging the