Leaking chimney

[matthlock]

Hi guys, I'm looking for some advice on a leaking chimney. Before Xmas I noticed that one side of the chimney in the loft was wet and slowly dripping on the loft board beneath it - not a lot but an obvious problem. I've had 4 roofers look at - 1st said that it was a common problem due to the position of the chimney not being on the very top of the roof, but also not far down enough to have sufficient leading and the water is running down into 'a table' and penetrating the roof; the 2nd said that it just need sealing; the 3rd said the chimney needs to be taken down but spent about 10mins in my back garden looking at it; the 4th said it also needs to be taken down and spent a little bit longer looking at it but still a max of 20mins. My friend has also mentioned that it may just be a bird's nest in the chimney holding the water.

I realise that it's hard to comment without seeing it, but do any of these sound right? It's hard to know what to do when the solutions and prices are so varied.

I've attached photos of the inside the loft to give an idea.

 

[chris_o]

I would hazard a guess that the flashing needs to be addressed around the stack

 

[matthlock]

That's what I thought initially, just some dodgy flashing. Don't want to pay £800 to take down the chimney if only £200 worth of flashing and sealing is needed. The two guys who said that the chimney needs to come down didn't even go up on the roof, they are just going on experience. The 1st guy took about 40 mins, went up on the roof, went in the attic, and even came back the next day to give me a proper write-out and show me all the photos he took. I obviously want the best jobs, even if that means spending more and taking the stack down, but I don't want to pay for unnecessary work.

 

[Burnerman]

Pictures of the pointing condition of the chimney, and the flashing from outside please!
John

 

[matthlock]

Hi John, I can't take photos of that as I can't get on the roof myself. Like I said, I appreciate that you can't really say without seeing the problem but how likely is it that the stack needs to be removed vs flashing and sealing? Surely whoever does the job should have looked on the roof, the two who said that the stack needs to come down didn't and just went by looking at it from the garden and inside the loft - I think they went on experience and similar jobs rather that looking at the specific problem. My gut instinct is to go with the 1st guy who spent time looking around everywhere, but I don't want to have to pay out later down the road if that's not going to fix the issue! I'll see if I can take some zoomed in pics tomorrow in the daylight.

 

[Burnerman]

Obviously, if the chimney is removed and the roof tiles / slates made good, that's the end of the leaks......however, it could be as simple as a gap in the flashing, a slipped slate, poor pointing or even the flaunching cement on the top that's causing the problem.
It doesn't matter if the chimney is not on the roof top, but naturally enough the upper flashing needs to be in good condition, and all moss or whatever cleared so it can cast the water away. From the state of your internal photos, I would personally expect the fault to be pretty obvious!
John

 

[matthlock]

Maybe obvious to you John but not to me. The water is only after some of the chimney as the other half of it is dry, and it looks like the water is running down the outside of it rather than penetrating through. The 1st guy said there wasn't as much flashing as there should be, and a few cracks in the cement. What do you think the problem is?

 

[chris_o]

That is quite a significant amount of water that is penetrating. Is the stack fairly easily accessible with the use of a ladder/ roof ladder?

Being that it is fairly significant, I would say as soon as you had a closer inspection of the stack the cause would be apparent. If it was me that went to have a look at the job, and the stack was accessible, I would get the ladders out to diagnose properly, not just throw ideas up in the air

 

[Burnerman]

I meant the fault should be obvious if you are standing around the chimney base, so apologies for any misunderstanding there!
I'd be looking for flashing gaps where the lead is tucked into the brickwork, poor cementing to seal the flashing in place, and then poor pointing where water is going through the cement bed, and coursing down behind the flashing.
All typical and usual faults - we need reliable and close up photos, really.
John

 

[matthlock]

Well as seen as the two roofer who said they would need to remove the stack never bothered looking on the roof around the chimney I'm not sure about them. It reasonably accessible with ladders I just haven't got any that big. The 1st guy took photos and showed them - I wish I took a copy now.

 

[matthlock]

I just spoke to the 1st guy, explaining that the other two has said the stack needs removal and he said that that is usually the last resort, especially when the stack is in good condition like mine. He also guarantees the work so I guess if it still leaks I have some comeback...

 

[Burnerman]

The first guy is talking sense - I'd go with him personally but that's dead easy for me to say! I hope the work goes well - if it ever stops raining
John

 

[rhino666]

Agree with Burnerman. You need a trusted professional to get on the roof and do the job, whatever it is anyway and from your posts it appears you have identified one.
I had a similar problem with my chimney where lead had been dressed around the chimney but not rebated into the blockwork. The flaunching around the lead had cracked at the back of the chimney and rainwater simply ran into the crack and then between the lead and chimney and into my loft - perhaps you have the same problem?