Waterproofer on part of wall. Tricky one

hail hail

hail hail

Private Member
Wee tricky one i have. If any of yas remember a chimney repair i did last year, im doing a follow up on it because there was a small issue raised. The chimney was taken down to near ground level because of a vertical crack appeared right up the wall. It was taken down to lintel level above the stove, and keyed out whole way up the wall and out the roof. Built back up in 4inch block, flues, vermiculite etc.. and floated with sand&cement right up the middle which had waterproofer in it then skimmed to an old traditional cottage finish.

On the left hand corner, theres a patch appeared that looks like damp to me, but its in the old blockwork and not on the new block/plastered area. I can see the outline between old and new!

Im trying to get to the bottom of it to see what the cause is. I dont think its something to do with the work and its coming in the roof somehow but id thought id ask this question anyhow. Can damp come in where the gable meets the roof, travel down the blockwork behind the floated/skimmed area and show up in a corner where the wall hasnt been plastered with waterproofer. I know this sounds really silly but i thought id ask anyway. The reason why im asking, the damp(if it is damp) is on the old block wall and not on the newly repaired part going by the outline of it. Its somehow showing on the old section of the wall which has me thinking about traveling down behind the plasterwork.

Sorry about the bad pic. Phone shite, broke 3 decent phones last year so go to work with a dicky one now.


Waterproofer on part of wall. Tricky one
 
Also forgot to mention, the sky man has bolted his dish to the side of this chimney. Im thinking maybe hes the cause of it.
 
vfr12 said:
Very likely.
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Its a tricky one. All my work is up the middle and above the roof where teh stove is and this patch is appearing on the left hand side where my work isnt(apart from the over skim) Theres another small football patch up 3/4 way on right side but again, its on the old block. All block work, Lead, floated and skimmed all done to standard so this one has me baffled!
 
hail hail said:
Its a tricky one. All my work is up the middle and above the roof where teh stove is and this patch is appearing on the left hand side where my work isnt(apart from the over skim) Theres another small football patch up 3/4 way on right side but again, its on the old block. All block work, Lead, floated and skimmed all done to standard so this one has me baffled!
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hahahah when did plastering get so technical !!!!

i dont know the answer ....but how much do you want for the burner ???
 
Check the obvious first any damage done by sky guy, roof tiles missing or damaged, gaps at the apex end/verge, ext render cracks damage, any old soot traps in areas behind stains ?
 
algeeman said:
hahahah when did plastering get so technical !!!!

i dont know the answer ....but how much do you want for the burner ???
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Tell me about it fs, I just need to get to the bottom of this as its been wrecking my head. I honesty don't think its anything to do with the lead,block,plastering. There was work done on the roof just around the chimney by a roofer with old slates but can't see how if his work is leaking then how is it leaking at the bottom corner.

If it was the plastering/lead above the roof, surely it has to come straight down the wall rather than magically going behind the new plaster and appearing where it is.

I just thought id share it with yas to get other plasterers opinions on it.
 
Smudger1 said:
Check the obvious first any damage done by sky guy, roof tiles missing or damaged, gaps at the apex end/verge, ext render cracks damage, any old soot traps in areas behind stains ?
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What do you mean soot traps? All the old chimney was removed.
 
hail hail said:
What do you mean soot traps? All the old chimney was removed.
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Right i read you wrong when you said stains on original blockwork to side maybe soot leached through into original block/wall from old chimney breast, just gotta think out box when all the obvious is checked before digging into it to see whats going on behind plaster, if it was stone wall then rain, damp could come in higher and travel through the maze of joints and show on surface further down but unlikely in newer dense block work , you tried moisture meter on it to see how wet and possibly direction its getting fed from ?
 
Smudger1 said:
Right i read you wrong when you said stains on original blockwork to side maybe soot leached through into original block/wall from old chimney breast, just gotta think out box when all the obvious is checked before digging into it to see whats going on behind plaster, if it was stone wall then rain, damp could come in higher and travel through the maze of joints and show on surface further down but unlikely in newer dense block work , you tried moisture meter on it to see how wet and possibly direction its getting fed from ?
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Na, no moisture meter. Tbh, I've never used one.

What you mean what direction getting fed from?
 
hail hail said:
Small cottage and you can see right up to the peak inside. Chimney is about 1m up through the roof.
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i wouldnt loose any sleep over it....its not worth picking your brains all night over some elses problems/fuuck ups.

im sure they wouldnt worry for me or you.
 
algeeman said:
i wouldnt loose any sleep over it....its not worth picking your brains all night over some elses problems/fuuck ups.

im sure they wouldnt worry for me or you.
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I know but tbh, I have an excellent reputation and hate letting people down. Even if it ain't my fault, I'll help them get to the bottom of it. I know some would just walk away but it isn't me.
 
Sounds a silly question but if was a bit damp could be that bit just trying to bleed through
 
hail hail said:
Na, no moisture meter. Tbh, I've never used one.

What you mean what direction getting fed from?
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with a good moisture meter you can see where water/damp is highest if at bottom of stain but fading as it goes up the wall its feeding down , if central like a bullseye but fading around center then its coming through straitish maybe off a wall tie.
sounds like probably sky guy or roofer work to fix it ?
 
flynnyman said:
So the area that is damp is existing and you only reskimmed it? Is there a void behind it?
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Chimney was taken down to lintel above stove. Old block that was left was like a V shape.

Chimney built back up as should be. On the V shape, there was old plaster. On the new V shape built, was block,flues etc.., Then scratched with S&C with float and pins ready for skimming. Let dry. You could see old and new.

PVA over it and skimmed all wall in old traditional style plaster to match rest of cottage.

Above chimney was scratched, beaded SBD lead work. Capped with concrete cap with DPC all under cap tucked up around flue. Filled void with fondu/concrete mix. Cut very thin line of tucked dpc and filled with sealent. Chimney cowel installed.

Now there's a damp patch appearing in the left hand corner on the old block. If you see keyed out block(not exact but has the shape of where old block meets new). This wasn't here before the rebuild.

I'm thinking, if tge lead was teared or pierced when installed, then it should come straight down but this is appearing more on left hand corner.

TBH, I'm 99% sure it isn't my fault. I was just wanting to know, if it was coming in where lead is, can tge damp run down behind new plaster work then appear on old where it meets. I'm 99% sure this couldn't happen because I've never heard or seen it happen before but thought best to ask here to reinforce what I think.
 
It's difficult (impossible) to give any meaningful answers without seeing it. However there are a few things it could be.

Have a look at the verge boards which sit between the tiles and the top of the gable. Looking at where it is I'd also have a look at the wall face on the outside as it looks to be around the point where the purlin goes into the wall. The other thing is that it may be tracking down a joist and stopping where it meets the purlin.

A few photos of the outside would help a bit, but the point is the water ingress will be at or above that point. It's time for a ladder or a cherry picker and see what's what with the tiles at the top of the gable.
 
Looks like that is the width the chimney is going out through the roof at that point, so either the lead tray is too low, or likely no lead tray in it, have seen this before where tray was too low, so moisture gathers up in tray and seeps into room instead of seeping down the roof, but if no tray in they should take chimney down and build one in
 
flynnyman said:
Yes pics of outside and any of in between will make it a bit clearer,
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Will do next time im there.

Big said:
Looks like that is the width the chimney is going out through the roof at that point, so either the lead tray is too low, or likely no lead tray in it, have seen this before where tray was too low, so moisture gathers up in tray and seeps into room instead of seeping down the roof, but if no tray in they should take chimney down and build one in
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No, its not coming through the roof at that point. If you look at the pic, its coming out the roof above the stove, not where this patch is. I know what your saying but it isnt it that because if it was getting in at the side of the chimney, it would be further up and more to the centre.
 
Pagey said:
Was wall damp when you went over it or bone dry?
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No,


Pagey said:
Sounds a silly question but if was a bit damp could be that bit just trying to bleed through
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No, this chimney was dry after built, painted and left for months and only appeared these last week or to. I was up at this holiday cottage few weeks after xmass and this patch wasnt there. Its only appeared this week or last.
 
hail hail said:
No,




No, this chimney was dry after built, painted and left for months and only appeared these last week or to. I was up at this holiday cottage few weeks after xmass and this patch wasnt there. Its only appeared this week or last.
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I've had a few jobs in the past where it looked alright to go over and I have done as normal then a patch of it took ages to dry that was my only thinking behind my question
 
I don't know where it is coming from but I wouldn't rule out anywhere because it's coming through on the left. You rendered the middle with waterproofer? Possibly leaking somewhere above, Blocks bricks now saturated, and the original is just a weak point that it's coming out of?
 
Hey hail,has the chimney got a pot on?it could be the flornching around the pot,flashings I have traced damp to long screws and nails before in the past it could very well be the sky dishs fixings but would say absolutely nothing to do with your work man,unless driving rain is getting between slate and facia.
 
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