Mira Bar Shower leaking into wall - best way to repair?

[tlangdon12]

My step-daughter bought a 50's end-terraced house at the start of the year, and found there was a leak from Mira bar shower that was coming through the bedroom wall from the bathroom on the other side of the wall. The shower is over the bath and the bathroom walls are tiled around three sides of the bath.

I had a go at fixing the problem by removing the shower from the wall, removing the large format tile that the shower bar was fitted through, and had a local plumbing firm come in to provide new tails for the shower. The tails come up from under the bath in a chase in the blockwork. I then fitted new mosaic (Travertine) tiles on a cement backer board over the tails, and refitted the shower with a genuine Mira fitting kit. The new mosaic tiles and the orginal tiles were both sealed with a silicone sealer from Toolstation.

Three months later, she has just moved the chest of drawers that was against the bedroom wall, and found that the wall is really damp! The shower is still leaking! The pattern of the damp patch suggest that it is pipe on the right-hand side that is leaking, and it leaking very high up, e.g. directly behind the bar valve. There is no sign of any leak from the front of the valve.

I need to advise her on how to get this repaired. I can't face taking the mosaic tiles off the wall, and am inclined to think about creating an access panel to the pipework in the bedroom. The wall is a light cinderblock construction, and is only about 90mm thick including the two layers of plaster (so possibly built with a 3 inch wide block?). The guy from the local firm blew through the back of the wall when he fitted some red wall plugs to fix the new copper pipes/tails to, so the wall is quite fragile in the area directly behind the valve.

I think I can excavate through the wall to get to the pipes, and then see where the leak is and get the plumbers back to repair the pipes from the bedroom.

I them propose to fit a timber frame work for an access hatch in the bedroom so that we can continue to monitor the pipes to prove that the problem really has been fixed.

I have a couple of questions:

1. it is likely that the plumber will be able to repair the pipes working from the rear?
2. should I be considering installing a small lintel over the access hatch?

The wall isn't load bearing; the joists in the loft run parallel to the wall, and there is nothing resting on the wall in the loft other than the ceiling. I was thinking a light duty (or extra-light duty) lintel would be sufficient to hold up the blockwork above the acccess panel. The panel is only going to be 50mm wider than the width of the bar valve, and my excavations will only go as far as the chase on the other side, as I need to retain as much blockwork as I can to support the tiles on the other side of the wall!

Below are photos of the bathroom wall with the shower valve, and the bedroom wall that is directly behind it.

I'd be grateful for any thoughts, answers and advice.

 

[Ben-gee]

One solution would be to abandon what is in the wall, disconnect it under the bath.

Drill through from the bedroom to under the bath and connect to the hot and cold. Run two pipes on the surface in the bedroom and drill two new holes from the bathroom to the bedroom. Bring through plain pipe and use a front fixing bar valve kit (pair of 15-3/4” adaptors, fixing plates and covers).

This could all be boxed in in the bedroom.

In the bathroom make good old valve position as you wish, simplest is to leave the old cover plates and just replace the bar valve with two chrome 3/4” female end caps.

Having said all that my first solution would be to do what has already been attempted!

The above solution I have done a few times, usually backing into an airing cupboard or built in wardrobe - so not really a problem the non bathroom side.
Another was into a utility room and the pipes were just left exposed.

 

[tlangdon12]

Thanks Ben-Gee. It's a good option for us to consider. The advantage is that it's much simpler and avoids the time/cost/risk of a lintle. Access under the bath is quite resticted, so connecting pipes down there might be as tricky as working in the wall, but at least you can see that its not leaking when you've made the connections under the bath.

 

[Julie Street]

Much easier than that is to replace your bath mixer tap with a thermostatic deck mounted bath shower mixer tap.
Cap off the feeds to the bar mixer under the bath, leave the empty pipes in the wall. Get rid of the bar on the wall, replace a few of the mosaics.
Job done.