Condensation or leak?

[Leadman]

Hi Guys,just wondered if you have any ideas, had a guy call me in July to look at some leaks he had on his property which was built cira 1900's the roof had been re-slated 5 yrs ago and the lead work around the chimneys wasn't the best but also not the worst i had seen but on closer inspection it was agreed that the back gutters and flashings would be replaced, the back gutters on the chimney had been dressed around and had split so i figured that that was where the leaks where from being the chimney breast was damp(all of them)
Any way i quoted him a price to weld the back gutters and replace soakers and side flashing, this must have been too much because he got someone else lol.
I got a call the otherday to say he still has the problem and would i have a look, i asked the usual questions to make him squirm a bit lol( what happened, why don't you get the other guy back etc.
Had a look today and the guy has replaced the back gutters but not welded them but the problems still there on his new plaster!
Now im not sure this is the lead now, although all the chimneys have ventilation grids in them and have cowls on the top im just wondering if its that they don't have a lead damp prof course above the flashing?
Any answers Guys?
Cheers Dave

P.S. I have told him i will strip out the slates around a chimney in the new year and see if i can uncover any thing.

 

[noseall]

hygroscopic salt saturation

 

[Leadman]

Hi Noseall, can you explain abit more for me?
Cheers
Dave

 

[2face]

serves him right for picking your brains then getting an idiot in

i love it when this happens it gives me great pleasure.

 

[noseall]

chimneys whose age is greater than say 20 years (pre-gas) and have been subject to a lot of traditional fires i.e. wood and coal, then there will be a large amount of hygroscopic salts deposited within the masonry.

these salts eventually saturate the masonry and migrate to the surface.

hygroscopic salts absorb moisture from the air and reveal themselves as yellow/brown staining on the surface of chimney breasts.

a leak is usually the first line of inquiry particularly near roof level, but is not always the case. if the flashings are sound then i would look towards hygroscopic 'bleed'.

 

[noseall]

serves him right for picking your brains then getting an idiot in

i love it when this happens it gives me great pleasure.

i get no pleasure, only disheartened. it tars everyone with the same brush.

"typical roof££££rs, only interested in ripping you off".

 

[justlead1]

Hi. We have no end of calls with the problem you describe. 80% being when roof space has been converted into accommodation, it is only then that the dampness becomes apparent. The fact that the chimney has been damp for decades gets miss when it got 8 or 10 foot of warm loft to dry it out prior to showing in rooms, although this is sometimes the case in severe situations. Coupled with the fact that we do not have permanent open fires as was the case when originally built. The intensity of rain seems greater of late. Houses constructed with cavity walls and all the dpc closures to window,heads of window, doors etc. use brick chimneys with no dpc (strange) All these facts create the problem. Fitting a chimney tray dpc will cure the problem but at a high cost, it requires scaffold the demolition of chimney above roof, fitting tray and rebuilding and new lead flashing. Average price £1650-00
However coating the external chimney with a transparent sealant will help in the short term. If the aesthetics are not an issues rendering the chimney down to soaker /cover flashing level and then paining with good quality masonry paint will get results.
I have made a video about the fitting and performance of chimney trays/dpc which can be viewed at http://www.justlead.co.uk once on site click on News & Video scroll down to the appropriate video. Good Luck

 

[Leadman]

Hi Guys, thanks for all the replys.
Noseall thanks for that,i have had that in my walls the dry salt deposit when i dryed out a leaking door frame 8 months later a salt deposit appeared, i thought the damp had returned but it was bone dry! i just didnt know the name of it.
Justlesd , thanks also for your reply, personally i think that the chimney will need a damp proof course, but these are big chimneys and as i said before he didn't want to pay my prices for a proper job before and i cant see him going for this be we shall see!( great video on your web-site too)
As for serving him right im not so sure,sire he went for the cheaper price, haven't we all at sometime, but to be honest i would just like to find a cure for this, i see it as a challenge and not really the money although of course it always helps!
Thanks again
dave

P.S. i will let you know what i find when i strip the slates off around one of the chimneys.

 

[justlead1]

Hi. Leadman
Thanks for your kind words.

Although we do not travel away form Cornwall now to fit sheet lead work, we do supply all over and also get asked to carry out work which i decline. If you wish i can put your name forward for any thing in your area? Good Luck

 

[Leadman]

Just an up date, i went back and removed some slates around one of the chimneys around the back gutter and although it wasn't the best back gutter i've seen the lead was doing its job!
The problem i did find was the chimney, when i scraped off the pointing and tryed the damp meter as far in as i could push it it went haywire!
any way advised the client of the cost of putting in a lead slate and could see his eyes glaze over lol.
Another problem was that the roof was close boarded and even though they had used beather felt it couldn't do its job, i have advised installing slate vents and pulling back the insulation at the eves to get an air flow.
We shall see what he says!

 

[noseall]