Wall with damp patch on it - advice reqplease-Richard C

[r896neo]

I'm certainly no expert on wood burning stoves but i would have though not insulating the flue is a very bad idea and could result in condensation in the flue and therefore potentially the reason your damp is getting worse.

as mentioned in previous posts it takes vcery little moisture in a chimney to bring out the old salts and cause staining. Did the fitter suggest any reason as to why he didn't insulate it?

Maybe change the title of this thread to include 'Richard C' as i think he is pretty clued up on all things stove and could give better advice than me.

 

[GJUK]

Thank you for yor reply
Please excuse spellings I'm doing this on my iPhone.

The betas qualified installer advised not to back fill with vermiculite in case the chimy was damp. Remember I have seen water coming down it during rainfall.
He has vented it at the top to allow the chimney to breath, that's the idea anyway!

I know I started this thread almost sure that the damp was due to water running down the chimney. But now next door has a similar issue I'm stumped. Their chimney is totally blocked off and he is saying it's his facias which are not allowing air flow.

Please help me!!!

Thanks,

Jon

 

[r896neo]

Unless you share the chimney the fact that your neighbours have the same problem may be irrelevant. Facias and Soffits are primarily vented to reduce the decay of rafter feet and other timber up there. Not having them vented could rot some of the timbers prematurely but it certainly would not cause damp. Unless your roof is leaking water should not be getting into the soffits at all really.

Some photo's of the chimney stack would probably help. The only ways for water to get into a chimney from above are poor pointing, poor flashings poor flaunching or incorrect or non existant capping of the pots.

You need to get someone you can trust to get up there and give it all a thorough going over and then If you can be certain none of these areas are responsible then you have to look a bit more left-field. It would be fair to assume damp is not coming from below as it would exhibit further down near the base worse.

I have said it before and it is worth repeating, salts in the flue caused by burning over the years only take the smallest amount of water to reactivate them but the growth of them can appear to be terrible damp when in reality the volume of water is very small. You need to consider leaving this to hopefully dry out for 6 months or more and then redecorate. If may even require replastering of the chimney brest internally with waterproof render.

 

[GJUK]

Thank you very much for your reply.

The fact that when I removed the gas fire in the ground floor living room and saw water dripping down the chimney when it rained is a sign to me that water is getting in to the chimney.

If this small amount of water can cause damp like patches, due to the burnt residue then it sounds the most likley case.

I have had a wood burner installed now, with a new flue lining and chimney pot, all being wel lthis is now sealed

I have a friend who is from building regs popping over to have a look at the roof for me in a week.

I might just get the flashing replaced while the weather is dry just in case it is this as it seems the most likley cause.

Thanks

Jon

 

[Nige F]

Replace the flashing 9 times out of 10 they need re pointing not replacing My chimney leaked the same and I poured loads of water seal round the flaunching/pot as a temporary measure - still going after 2 years - where water can get in the silicone fluid does - then seals

 

[GJUK]

just an update.

My surveyer mate came and had a look, and has advised its my secret gutter and flashing which needs replacing.

So, thats the next job!

J

 

[GJUK]

photo of chimney.

 

[Nige F]

that secret gutter is so secret I can`t see it No tray through the chimney either Hard bricks , soft pointing failing. need a tidy up You`ve got the 10th one that does need a new flashing

 

[GJUK]

chimney tray, what's one of those?

Thanks,

Jon

 

[Jay138]

Lead trays & chimney flashing:
http://justlead.co.uk/chimney-flashing.html
google it if you don't trust links!

Sorry 2 chirp in but my next door neighbour has been a roofer for nearly 30 years, for the last 5 years on and off I have worked along side him learning the roofing trade so to speak....
First of all I would advise you about the roofer who went up and checked out the roofing for you, well don't have him again!!!!!
He should of checked out the pointing around the stack and all the lead work around it also,
That didn't suddenly start looking like it is overnight!!
just by looking at the photo I'd say it needs work done to the lead, and I promise you when my nieghbour comes back from an easter weekend away then I'll show him this thread and get him to comment on what he thinks the problem is.
And like I said he has 30 yrs experience under his belt!!
I hope you do cure this problem of yours buddy... if not then you could always turn it into an interior water feature! lol! sorry my sense of humour flashed past me then!!

 

[GJUK]

Hi All,

Bit of an update on this.

I still have the damp problem but have done the following:

Had the flashing replaced (over standard) and then inspected by a loss adjuster friend - confirmed its been done well.

Had a wood burning stove installed.

I've noticed that since unsing gthe stove recently (curing this cold but DRY spell) the damp is coming back again.

We've had no rain so it can't be water coming in from the top.

I'm really having problems and want to get this sorted, the heat from the installed chimney flue perhaps could be pushing out the old damp in the bricks? Out towards the plaster layer?

Can someone help me please ?

Thanks,

Jon

 

[tim00]

What does "over standard" mean when you say that you've replaced the stack flashing?.Those tiles should each have an individual soaker with stepped, cover flashing above - has this been done?

I dont see any felt lapping into the gutter - is there felt under the tile?

Why and when was the PVC fascia and soffitt installed?

 

[joe-90]

I see this sort of thing all the time. It's all to do with physics. Warm air holds more water vapour than cold air - hence the heavier rain in the tropics. What you have happening is warm moist air from your house (breathing, drying hair and clothes, cooking etc) goes up you chimney and when it cools it turns back into water and bleeds through your bricks. On an industrial scale this is how the big power station cooling towers work. You need to stop the warm air getting up the chimney - or do the opposite and put an air brick in that will let that much air go up it will dry out the condensing water vapour. Simples.