Do I need a plumber or a roofer to track down where this leak comes from?

[RedTomato]

Hi, I have damp coming through an upper wall. It could be from a shower or from an exterior chimney stack. Pics attached. House is a 1930s London semi, brick walls with no cavity.

First pic is the kitchen wall. The bathroom shower is directly above this.

Second & third pic is the upper staircase wall. A pencil line has been drawn around the damp areas. The bathroom shower is on the other side of the left wall. The exterior chimney is on the other side of the wall.

Fourth & fifth pic is the exterior chimney. You can see where it was patched about 6 months ago.

No pic of the shower - it's covered in tiles and no damp is visible. Could be a leak in the shower plumbing moving through wall bricks (the shower valve is embedded in the exterior wall).

Thing is, I've already had a plumber and a roofer in to do repairs, both were mediocre and I don't want to contact them again.

Any recommendations as to how to find the right sort of person or company to investigate and properly track down the leak?

 

[Hugh Jaleak]

Is the chimney ventilated? I'm not an expert on flues, but if a Chimney is to be capped off, it must be allowed to breath top and bottom.

 

[RedTomato]

Is the chimney ventilated? I'm not an expert on flues, but if a Chimney is to be capped off, it must be allowed to breath top and bottom.

I have no idea if it's ventilated. Probably not. Kitchen fireplace was removed decades ago when electric cookers came in, before my time. I had top chimney stack removed a few years ago. The damp started a few months ago so unlikely to be related.

 

[Madrab]

Render has obviously been repaired, only really needs a vent if it's open to the top. Was the stack completely removed to below roof level and the roof re-tiled properly? How was the old builders opening sealed? You may need break into the old builders opening and check out the integrity of the chimney up to the roof to make sure it's hasn't been breached if you can't access from the attic.

I that's all dry then it's over to the shower IMO.

Chimney specialist and then a plumber

 

[Tigercubrider]

Why is that area of the chimney so black?

 

[Madrab]

Why is that area of the chimney so black?

It's where the rainwater runs down. That's acid rain in the dusty, car exhaust ridden cities for you.