Leak on wall behind shower

hopskipandjump

I had a leak last year in my bathroom, which I only discovered because skirting boards started to rot. I live in a bungalow and had changed my bathroom 5 years previously. It transpires that the shower tray wasn't sealed properly and it eventually rotted some skirting boards and I was left footing the bill to rectify the situation.

I didn't use that shower from early July last year up to the middle of November so the walls were well and truly dried out. In January this year, I noticed a funny sheen on a wall in the hall approx. 6 feet up the wall and discovered mould and fur on the wall behind a hanging picture. This wall is directly in front of my shower, which is probably at 7 feet. There is nothing obviously damp about the wall otherwise. I hung another picture a few weeks later to discover that fur was beginning to grow on the wall again. The paint on the wall was beginning to bubble and it fell off very easily when I scraped it. The bubbling paint is now rising higher on the wall despite the fact I'm not using that shower, nor do I have any picture on that wall. I asked my plumber to look at it a few weeks ago but he didn't call. He's due to call in the next few days. He said I'd just have to rip off the tiles on the bathroom wall to find the problem, which totally and utterly maddens me as I don't have that many spare tiles at this stage and I don't want to do it unnecessarily, nor do I think I should have to pay for it!

Would anyone know what could be causing my problem, everything is sealed in the shower at this stage? The only thing I noticed when I looked at it last night is that the showerhead could do with being screwed in slightly tighter in to the wall (it's a rain head that comes out from the wall). Could it be that a bit of water has been dripping down the inner cavity of the wall from where the shower is screwed in that has caused this problem? I'm reluctant to rip more tiles off the wall, I really don't know if I would have enough tiles to re-tile as my tiles are large and staggered every second row, I'd have to take off more than just one straight row. I obviously want the problem permanently fixed though and will have to do whatever it takes to get it done.

Thanks

QBE

you say the wall at the back of the shower is where a picture is fitted. Is this a studed wall or a solid wall? you could remove the plaster slab to identify any issues from that side and make good plastering repairs and decoration. That will not interfere with your tiles.

Do all the basic tests first. Remove bath panel and test for signs of water under the bath. This Can identify what area water is coming from above the bath as well as any below. Check that a proper seal is made around the shower body and head.

Removing the bath bath panel(if the shower is above the bath and removing the slab at back of the shower wall. Will help mitigate casing unnecessary damage to the tiles. If the pipe work can be pressure tested.(that will help identify its not from the domestic water supplies) and a moisture tester will help you get to the route of the problem.

If the wall is a solid wall. Mitigate the need to break tiles by using the moisture reader where you get the highest reading.

Also is the shower/bath base solid and seals made good around the bottom of the appliances. Was the correct waterproof grouting used? it could even be a codesation problem from lack of ventilation in your bathroom or (believe it or not your attic or any space that's above that room ) Invest in a moisture tester . it will be the best few quid you ever spent to sort that out.

Hope this helps....

QBE

sorry. I should have said anyone that specialises in the hammer and chisel investigation of leaks in bathrooms. Before spending at least an hour assessing the water damage and leak with proper equipment. Should be avoided or budget for a whole new bathroom.

Also if the leak is from pipework in the bathroom and not due to maintenance issues like faulty bath seals or leaking tiles or condensation. Your insurance provider may pay for the trace and access of the leak and the repairs to the associated water damage. You need to source the cause of the leak first in order to pursue an insurance claim.

Just to add an example that it could be anywhere and a moisture tester will help you. Here's one I came across recently in a friends house after 3/4 guys (pros) had a shot finding it. Id have loved to have taken photos to post the pictures here. The bathroom was taken fully apart , carpets and floors/skirting in the bedrooms and some of the ceiling in the kitchen below.
The leak was coming from a flexi vent pipe in the attic that was connected to a roof slate vent. When it rained the water got in the roof slate vent and was leaking out of the flexi hose pipe that was connected to the 4" soil pipe. It would travel down the internal soil pipe in the boxing and into the bathroom. Now all that was need was a proper roof vent fitted and tighten the clip on the flexi hose .

hopskipandjump

Thanks for the reply QBE. The shower is freestanding, the wall is concrete. The shower is located immediately to the right when I walk in to the room, the showerhead being on the same side as the door so it's backed on to the wall in my hall. The shower tray is definitely sealed correctly, I had a leak due to poor sealing and that got fixed late last year and this problem only arose this year. I now remember taking down the showerhead to clean it while the shower was out of action and I'm beginning to think that the showerhead could do with being tightened in to the wall a little bit more and that's probably where my leak is coming from. The wall isn't wet at all, it's something that's inbetween the cavity block. There's no sign of the tiles coming away from the wall either. I took a photo but don't know how to upload it. I'll enquire about a moisture tester tomorrow.

agusta

Hi,My opinion on your problem would be..

Mould on a wall is a result of a damp wall,its doesnt have to look wet,your wall is more than likely 4 inch solid block not cavity block.This is a medium for moisture to travel mostly downwards.The mould is on the opposite side of the to the shower head which means you are on the right track.The fitting that you have for the shower head has two joints which could leak.
Joint No 1:where the rainhead screws in to brass fitting on wall.The fix would be to remove rainhead and fit ptfe tape on threads and refit and tighten fully

Joint No 2:A pipe runs from the shower mixer to the rain head brass fitting,this is the other joint on the rainhead brass fitting.It may have been disturbed when you removed shower head.The fix would be,cover shower tray with plywood,remove tile around shower head fitting by cutting grout line with diamond disc and breaking tile in the center and remove,make good joint and refit new tile.
Hopefully the minute leak is joint one.
the leak you have only leaks when the shower is on,ie when water is went to the rainhead,hope this helps

hopskipandjump

Thanks agusta. I had my boiler serviced this morning and ask the guy servicing it if he would look at the shower. He told me the shower wasn't screwed in to the joint in the wall correctly, it needed sealant on the threads which he kindly did for me and no tiles were harmed in the process! I'm so happy to have the problem fixed and to get back to having a decent shower again. As I hadn't used the shower for the past few weeks, I could see that there wasn't any more white fur growing on the wall and what was there had dried to a powder so I new it had to do with water somehow leaking from the shower.

agusta

well done