Infuriating leak

[Owen74]

Just seen this post. Do you still have the issue?
I cannot offer a specific answer but all the chat has been around leaks or water ingress. I wondered if you'd considered condensation, formed internally, as the cause? If you cannot see any way that water's getting in, maybe it's not getting in. Maybe it's forming on a surface internally and dripping down inside. I suggest this because it's been happening to me. I have persistent condensation on the underside of a roof valley which can drip down on to ceiling and on walls. (Notably, what rung alarm bells for me - this is always worse for me when it rains!). May I suggest you look for any smooth surface - pipe, valley, anything - in loft space and see if there's a buildup of condensation.

 

[DavidBoring]

Just seen this post. Do you still have the issue?
I cannot offer a specific answer but all the chat has been around leaks or water ingress. I wondered if you'd considered condensation, formed internally, as the cause? If you cannot see any way that water's getting in, maybe it's not getting in. Maybe it's forming on a surface internally and dripping down inside. I suggest this because it's been happening to me. I have persistent condensation on the underside of a roof valley which can drip down on to ceiling and on walls. (Notably, what rung alarm bells for me - this is always worse for me when it rains!). May I suggest you look for any smooth surface - pipe, valley, anything - in loft space and see if there's a buildup of condensation.

Hello. Thanks for your reply. The issue isn't resolved...yet however I'm 90% sure of the main cause and you're spot on. To cut a long story short, when we moved in a builder who was doing some work for us took down an old chimney stack as it was (seemingly) of no use anymore. What we have subsequently realised and I fail to believe he didn't notice this at the time, is that the kitchen oven extractor fan vented up a flue through this chimney. When they took the stack down they simply sealed the chimney at loft level therefore all steam, etc has been hitting the loft and underside of the roof and condensating there. Obviously worse in winter when it's colder but it also rains more then which has confused the matter. To prove the theory I've set off some smoke up the cooker vent and they appear in the exact position of the 'leaks'. It's only taken about 6 years to figure this out! Some people, the roofer included, aren't convinced but it makes sense to me. Anyway he's agreed to fit a flue vent so fingers crossed that should be that. Thanks for your interest.

 

[Owen74]

Wow, what an epic situation you had, well done on the self-diagnosing and experimenting with smoke etc. It sounds certain that your new flue vent will sovle it.