New water leak in loft/chimney after building work

[aliho]

Hi all

I'm in the top flat of an end of terrace Victorian house.

We had the cavity wall ties replaced four weeks ago, and the wall repointed including the stack two weeks ago.

The builders inspected the chimney, haunching and tiles while they were up there and said everything was in good repair.

During the recent heavy storms I noticed a water stain in my top front room on the chimney stack - between the picture rail and the ceiling. This is a new leak.

I went up in the loft and cleared out any fallen bits of sand rubble (we'd had water ingress in the back bedroom before the building work and doing this seemed to sort the problem out)

More heavy rain last night so I've been up in the loft and had the boards up.

The woodwork is damp and there are a couple of holes in the stack at floor level but I can't see any holes any higher up.

To me it looks the joists are damp at the top but at the bottom so I'm mystified how the water is getting into the room below.

I've attached a few photos.

Can anyone shine a light? What should I do now?

Best wishes
Ali

 

[CBW]

Any more photos - these don’t reveal much, but it appears the wetness is from below rather than dripping onto it? You might have a cracked tile, or it could be through capillary action.

 

[aliho]

Hi Chris

Thanks for taking the time to reply, I do appreciate it.

I've added a couple more images.

In IMG_20211020_134633296 you can see the damp joist and a hole in the chimney stack to its side. This hole is directly above where the staining is in the lounge. Any hope it could be coming through this (gaping) hole? The wall ties work was pretty violent, and then all the grinding out for the repointing, maybe a brick came lose at some point.

In the same pic, if you look in the alcove - this joist is also damp, but there's nothing coming into the flat.

IMG_20211020_134603555 is a close up of the hole and the damp joist.

Any more thoughts?

With capilliary action - how the heck do you work out the source?

Best wishes
Ali

 

[Harry Bloomfield]

Do you know if the chimney is capped, or in use? It could be rain getting down the stack via the chimney, then exiting via that hole you pointed out.

 

[aliho]

Hi Harry

The chimney is capped - the original caps are still on. Builder said they looked old but there were no cracks etc.

I have a woodburner (didn't use last year) and downstairs neighbour has an open fire (she doesn't use it)

 

[CBW]

With capilliary action - how the heck do you work out the source?

That would be a difficult one, and would probably need quite a bit of investigation. Regards the hole, it would seem likely it’s an exit point for wherever the ingress is taking place.

 

[aliho]

Thanks very much Chris and Harry.

If anyone else has any views or has experienced anything similar, I'd really appreciate hearing from you.

Best wishes
Ali