Big leak in attic around chimney stack

[trevorbayliss]

I have a big leak in my mums house at the moment. It is the attic bedrooms and around the chimney stack.

About 3 yrs ago i had this leak and so repointed the front / back and side of the stack. All has been good ever since.

I haven't been up yet, but i am thinking it may be the large chimney pots which have been leaking. The haunching around them was broken 3 yrs ago and really needed replacing, but i just did the pointing at the time.

There are 6 big pots which are open on the tops. So i am planning on going up and taking these pots down and replacing with the small gas terminals and renewing the haunching.

1) How likely it is the pots and not the flashing ? The flashing seemed fine before.
2) What value do the pots have ? I thought they might be worth £30 each, so would pay for scaffold hire and sand/cement.

It is the left stack which has an issue.

 

[vinn]

Which is your stack in the pic?
Is it the LH one with what looks like a kind of parapet or left in place roof ladder?


Go up and photo the flaunching on top of the stack, and the stack itself, and the flashings, and post pics on here.
Removing traditional pots can cause the property to look odd, and "small gas terminals" might give even more future difficulties than the pots ever did.
The amount of work in renewing or changing the pots is the same.
And often, second hand pots are worthless.
You have a traditional house with traditional features - thats money in the bank when the house is sold on.
Dont disfigure your property in hope of spare change.

Pics of the leak signs in the loft rooms might also help?

 

[^woody^]

How likely it is the pots and not the flashing

About as likely as me coming around for tea on Sunday.

 

[trevorbayliss]

It is the left sided stack. My house has the open velux.

The damp is coming through at the apex of the roof (the highest point). The chimney is big and has 8 pots on it. There is also some damp around the left side of the breast when you are stood in the room. So looking at the photo it will be around the front of the chimney stack.

Is it usually the soakers which need replacing or the flashing tucked into the stone work ?

I know the pots are original, but if i have to break up the haunching, wouldn't it just be easier to take them all down and use the small gas terminals instead. I thought these will still let ventilation through.

I am hoping to get up there with my ladders on friday and so will take some photos.

 

[trevorbayliss]

I have been on the roof today and have some pics.

The first ones are of the inside:

 

[trevorbayliss]

Some photos of the flashings

 

[trevorbayliss]

The chimney pots and haunching.

The main leak is the right side of the stack. This haunching seems in better condition than the left side.

Opinions welcome. I am pretty sure i will be removing the chimneys and replacing with small gas terminals. A neighbour has done something similar. None of my flues are being used for any fires as all have been bricked up. They have the vents in place though.

 

[vinn]

You dont seem to understand what I've been saying with ref to your chimney stack and pots - you could end up giving yourself extra work & more expense doing things your way - just saying.

There is a "parapet" that presumably is on a party wall?
The "parapet" in the pic looks very odd. Why do you even have it?
It appears to have been plonked on top of the slates, and over the apron flashing at the stack - it should have a saddle flashing where it meets the stack, and be properly bedded and flashed all the way down to its finish at the eaves.
I'd imagine that water is definitely coming in under the parapet.

Water will also be entering the roof at the step flashings and soakers. Work will be needed.
Likewise, all the flaunching is in need of completely stripping and redoing. All of it back to brick.

 

[datarebal]

step flashing can not be effective in its current form.
chimney head is knackered
The slates on the adjoining roof do not course through so i guess that's why the coping is there. check slate size and gauge.

 

[vinn]

Good call about not coursing through but why do the copings appear to be a much later add-on over the original slating?

OP,

Some of the slating surrounding the stack will have to be re-arranged.
All slate off-cuts & lead clips to be removed.

 

[trevorbayliss]

The parapet is the division between my house and the neighbours ? It is the line of cement stones i think. No idea why it is there, but it has been there as long as my mum has (20 yrs). Is it not to cover up where different roofs meet. There isn't one on my other neighbours side, just this one.

My neighbours roof is in a terrible state.

Why do you think the water is coming in at the step flashings ? They all look pretty good.

This issue happened 3 yrs ago and so i thought it was all down to the pointing. So i repointed and all has been fine until recently.

I was thinking it was the chimney tops causing the problem.

So i will re do the chimney haunching, but want to get rid of these pots. Much less hassle with little breather ones. I am sure they will still ventilate pretty well. But Vinn is thinking this is a bad move? Is this because of aesthetic reasons or for potential breathing problems ?

And you think the parapet is causing some issue. What would you do in this case here? Do you remove the parapet and relay with new mortar ?

Her is another photo from the guttering.

I can do chimney top no problem, flashing is a bit harder, but doable. My mate is a builder and so i can get help. Would prefer to do this myself though.

Just had a thought, my neighbour has had some repointing works done on his roof and the odd tile replaced. I am wondering if they have done something on the parapet which has now caused water to leak into my stack ? Think he had work done in early autumn last yr.

 

[trevorbayliss]

Here is my video i took today. May show more info:

 

[vinn]

Well that last pic shows much more.

The slates are in better order than the early pics indicated but to re-arrange the soakers you will still have to lift some.
Any cracked or off-cut slates should be replaced.

The parapet will have to be lifted and re-bedded.

The last ridge tile usually has a saddle flashing?

Leaks entering on the neighbour's side might be presenting on your side?

 

[datarebal]

Good call about not coursing through but why do the copings appear to be a much later add-on over the original slating?

OP,

Some of the slating surrounding the stack will have to be re-arranged.
All off-cuts & lead clips to be removed.

I guess its possible the neighbour had their roof off at some stage, Reslated with a different size slate.. or got the gauge wrong! Used the coping to disguise the join.. note it is off centre..possibly

 

[vinn]

I doubt that the neighbour's roof has been off and reslated in different size slates. I think the slates are original.
I think that there are a few indicators that the neighbour's house was built separately or later than the rest of the terrace - it was certainly built differently.

But no roofer in his right mind would give himself possible difficulties by doing a new build on a terrace that looses the gauge - it would be as foolish as using two gauges on the same roof plane?

The coping is not off centre by the way - that is the join - which suggests that that used to be the OP's gable wall.