Does the stack flashing look ok?

[dishman]

This developed from another post in building but it is now more suitable in the roofing forum so would appreciate any input you guys may have.

I have suspected water ingress from the stack. I am trying to work out if it is sweating due to lack of ventilation or an actual water ingress from the stack at roof level.

At first I thought it was just lack of ventilation, but the damp caused in one room seemed get worse after a rain spell.

This has been an long term damp patch. I just removed a tonne of efflorescence from around the stack in the loft. Some of the battens around the stack and flashing felt a bit damp but the flashing itself looks good.

I did notice that some of the flashing on the underside of the tile bent down and away from the tile rather than being flat against the tile. Could this be directing water the wrong way?

There was also quite a bit of mortar on the lead shelf behind the stack. It is now clear as you can see but could this also have cause water to back up?

Anyway here are some pictures and a video of the other side.



The video is a bit choppy in places.

Link removed - sorry - I have pop up blockers and the upload site came up as safe on WOT. Did not realise it brought up inappropriate sites.

 

[Doggit]

It looks as though it needs repointing, and I can't see any DPC. The chimney looks as though it's been capped, and that means no ventilation, and in not being used, it'll never dry out. Water may be getting in under the flashing where it's lifted, but that'd depend more on the direction of the wind/rain.

 

[^woody^]

Water penetration from flashing and from a flue, and condensation have different appearances.

Brushing on a load of liquid water-proofer to the brickwork and capping will be an easy good start at diagnosing, and or curing.

 

[dishman]

Thanks woody, capping it to vent it was my initial way to approach it. It was increase in damp after rainfall that confused me, then the feeling of damp in the batons around the stack. The fibreglass insulation around the stack seems dry so if it is a leak or water ingress, it is not obvious where it is coming from.

Here are some pictures from the stack on the other side, I could not post a video so I have converted them to images, hence the lower quality.