Damp patch inboard of an outside chimney, with no obvious cause or
broken thing to fix.

Late-Victorian three storey, with an external brick chimney for the
old kitchen range.
http://quercus.livejournal.com/240103.html#cutid1
http://quercus.livejournal.com/32427...43408#t1343408
The chimney is capped at the top (paving slab), but unventilated at
the bottom. It has a lead gutter into the corner of the roof. Access
is a pain, as I don't have ladders to do it and there's also a
protruding conservatory beneath.
http://quercus.livejournal.com/324272.html

Had a laddery chap up there a while ago to tidy the other chimney
stack, and he reported no obvious cause.

Inside has been damp for some years, to the point of peeling paper and
the plaster starting to fail. As there's nothing visible outside, and
I plan to insulate inside anyway, I've now started hacking the plaster
off inside. I hope to find an obvious damp spot, otherwise to tunnel
out onto the roof from the insides (at least with an endoscope).
Pulling the plaster showed at least three vintages of plaster on
there, so I think it's an old problem with some partial repairs done
in the past.

Now I've found this
http://quercus.livejournal.com/32427...43408#t1343408
This is staring at the inside wall of the chimney, from the turn of
the staircase onto the top floor. There appear to be two holes into
the chimney from inside, as if they were flues(?), blocked off by
bricks placed into them afterwards. Beneath the lower one, there's
also a horizontal length of timber set into the brickwork beneath the
plaster. Support for the staircase? It's a bit low to be a plate
supporting the floor joists.

Why would my kitchen range chimney have "flue holes" in it two floors
above? Was this common? Some temporary construction measure?

Any thoughts on de-dampening would be welcome!

Andy Dingley wrote:
Damp patch inboard of an outside chimney, with no obvious cause or
broken thing to fix.

Late-Victorian three storey, with an external brick chimney for the
old kitchen range.
http://quercus.livejournal.com/240103.html#cutid1
http://quercus.livejournal.com/32427...43408#t1343408
The chimney is capped at the top (paving slab), but unventilated at


the capping isn't big enough, you can clearly see cracking/algae at the
corner.
The capping should overhang the chimney by about 3 - 4 inches all around,
which means hoiking a 3X2 flag up there like I had to do last week on a
church chimney.

Enjoy

On Sat, 1 Sep 2012 11:21:46 -0700 (PDT), Andy Dingley wrote:

Now I've found this
http://quercus.livejournal.com/32427...43408#t1343408

Well from the bottom photo it looks like the really damp bit is the brick
of the chimeny and the immediatly adjacent bit of wall. I'm sort of
assuming that the expose bit of lath/plaster ceiling is the underside of
the bit of roof with the bodged mastic.

The cap doesn't look good it ought to over hang all the way round and
have a drip groove as well. 3 or 4" seems a bit excessive to me 1 1/2"
with the drip groove 1/2" in from the edge.

Personally the mastic is a bodge and that is where I suspect the water is
getting in. It will run down the outside of the stack and into the
rendermastic joint and behind the flashing. I think that of flashing
needs to be properly redone with the fall so water doesn't pool (if it
does) and up under the rendering skirt.

I was going to suggest that you took the stack down to below roof level
and patch the roof but I see from other pictures that would probably look
really naff.


--
Cheers
Dave.

On Sep 1, 9:28*pm, "Dave Liquorice"
wrote:
The cap doesn't look good it ought to over hang all the way round

Thanks. That wasn't something I'd considered. I'd put a camera up
there because I suspected there wasn't anything up there at all.

It's certainly the next step to try and fix though (grim task though I
think it will be to fix). Do I have to put a bigger slab up, or can
I have the flaunching fixed?

If I do slab it, how about 1/2" cement board? (I have some, and it's
lighter)

Personally the mastic is a bodge

I think it's a bodge over a perfectly good flashing. It was only added
by the chap up there last, because he couldn't see anywhere else to
stick it and he wanted to do _something_ after all the faffing it
took to get up there.

In message
,
Andy Dingley writes

Snip..
Why would my kitchen range chimney have "flue holes" in it two floors
above? Was this common? Some temporary construction measure?

My two storey Victorian house has 3 flues to each chimney.

The kitchen range, first floor bedroom and ? I think it might have been
a boiler for laundry. Ground floor, ceiling level entry so not the same
as yours. Could it have been a retro fit metal flued stove for a
bedroom?

That chimney capping looks a bit iffy. There is no overhang to drip
rainwater clear of the render and no ventilation to clear internal
condensation.

Any thoughts on de-dampening would be welcome!

Someone with more knowledge will be along shortly:-)

Oh! I see they have already.

regards

--
Tim Lamb

On Sep 1, 7:21*pm, Andy Dingley wrote:
Damp patch inboard *of an outside chimney, with no obvious cause or
broken thing to fix.

Late-Victorian three storey, with an external brick chimney for the
old kitchen range.http://quercus.livejournal.com/24010...43408#t1343408
The chimney is capped at the top (paving slab), but unventilated at
the bottom. It has a lead gutter into the corner of the roof. *Access
is a pain, as I don't have ladders to do it and there's also a
protruding conservatory beneath.http://quercus.livejournal.com/324272.html

Had a laddery chap up there a while ago to tidy the other chimney
stack, and he reported no obvious cause.

Inside has been damp for some years, to the point of peeling paper and
the plaster starting to fail. As there's nothing visible outside, and
I plan to insulate inside anyway, I've now started hacking the plaster
off inside. I hope to find an obvious damp spot, otherwise to tunnel
out onto the roof from the insides (at least with an endoscope).
Pulling the plaster showed at least three vintages of plaster on
there, so I think it's an old problem with some partial repairs done
in the past.

Now I've found thishttp://quercus.livejournal.com/324272.html?thread=1343408#t1343408
This is staring at the inside wall of the chimney, from the turn of
the staircase onto the top floor. *There appear to be two holes into
the chimney from inside, as if they were flues(?), blocked off by
bricks placed into them afterwards. *Beneath the lower one, there's
also a horizontal length of timber set into the brickwork beneath the
plaster. Support for the staircase? It's a bit low to be a plate
supporting the floor joists.

Why would my kitchen range chimney have "flue holes" in it two floors
above? *Was this common? *Some temporary construction measure?

Any thoughts on de-dampening would be welcome!

If that chimney is out of use, I'd consider removing it and slating
over the hole.
It will always be a problem and always need maintenance. It could even
fall on a windy day at some time.

The cap is too small and the lead flashing has not been properly
installed.

You could consider some flashband as a temporary measure to fix both
problems.

In article ,
Andy Dingley writes:
Damp patch inboard of an outside chimney, with no obvious cause or
broken thing to fix.

Late-Victorian three storey, with an external brick chimney for the
old kitchen range.
http://quercus.livejournal.com/240103.html#cutid1
http://quercus.livejournal.com/32427...43408#t1343408
The chimney is capped at the top (paving slab), but unventilated at
the bottom. It has a lead gutter into the corner of the roof. Access
is a pain, as I don't have ladders to do it and there's also a
protruding conservatory beneath.
http://quercus.livejournal.com/324272.html

Had a laddery chap up there a while ago to tidy the other chimney
stack, and he reported no obvious cause.

Inside has been damp for some years, to the point of peeling paper and
the plaster starting to fail. As there's nothing visible outside, and
I plan to insulate inside anyway, I've now started hacking the plaster
off inside. I hope to find an obvious damp spot, otherwise to tunnel
out onto the roof from the insides (at least with an endoscope).
Pulling the plaster showed at least three vintages of plaster on
there, so I think it's an old problem with some partial repairs done
in the past.

In addition to the other comments, the flue needs ventilating top
and bottom, or it will gradually fill with condensation, which will
come through to the inside as a damp chimney stack. The vents can
both be to the outside, so you don't lose heat from the house up
the chimney.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andy Dingley wrote:
On Sep 1, 9:28 pm, "Dave Liquorice"
wrote:
The cap doesn't look good it ought to over hang all the way round

Thanks. That wasn't something I'd considered. I'd put a camera up
there because I suspected there wasn't anything up there at all.

It's certainly the next step to try and fix though (grim task though I
think it will be to fix). Do I have to put a bigger slab up, or can
I have the flaunching fixed?

If I do slab it, how about 1/2" cement board? (I have some, and it's
lighter)


No.
It needs to be heavy duty, if you put anything flimsy up there, the elements
will destroy it in short time or it will end up in next doors backyard once
the first gust of wind licks it


Personally the mastic is a bodge

I think it's a bodge over a perfectly good flashing. It was only added
by the chap up there last, because he couldn't see anywhere else to
stick it and he wanted to do _something_ after all the faffing it
took to get up there.

He probably knew the capping needed replacing but didn't want to do it, but
there's no getting away from it, however horrible a job it is.
You may need to hire a roofer and/or a cherry picker, failing that,
scaffold.

On Sun, 2 Sep 2012 11:49:33 +0100, Phil L wrote:

If I do slab it, how about 1/2" cement board? (I have some, and it's
lighter)

No.
It needs to be heavy duty, if you put anything flimsy up there, the
elements will destroy it in short time or it will end up in next doors
backyard once the first gust of wind licks it

Agreed and take note of the last bit. The 3 x 2 slab on the barn stack
was moved by the wind here and it only has a small over hang for the wind
to gat hold of. It now has some large screws into the stone/brick work
below. The OP's place looks as if it might be a bit exposed to SW'ly
gales coming up the Bristol Channel.

You may need to hire a roofer and/or a cherry picker, failing that,
scaffold.

Scaffold is cheap, I got the impression from some of the other photos
that the ground sloped by the base of the relevant wall so a cherry
picker might not have suitable access and it looked quite a way up as
well, cherry pickers wobble...

Also to easily point the the new slab onto the stack you need all round
access.

--
Cheers
Dave.

On Sep 2, 10:53*am, (Andrew Gabriel)
wrote:
In article ,
* * * * Andy Dingley writes:









Damp patch inboard *of an outside chimney, with no obvious cause or
broken thing to fix.

Late-Victorian three storey, with an external brick chimney for the
old kitchen range.
http://quercus.livejournal.com/240103.html#cutid1
http://quercus.livejournal.com/32427...43408#t1343408
The chimney is capped at the top (paving slab), but unventilated at
the bottom. It has a lead gutter into the corner of the roof. *Access
is a pain, as I don't have ladders to do it and there's also a
protruding conservatory beneath.
http://quercus.livejournal.com/324272.html

Had a laddery chap up there a while ago to tidy the other chimney
stack, and he reported no obvious cause.

Inside has been damp for some years, to the point of peeling paper and
the plaster starting to fail. As there's nothing visible outside, and
I plan to insulate inside anyway, I've now started hacking the plaster
off inside. I hope to find an obvious damp spot, otherwise to tunnel
out onto the roof from the insides (at least with an endoscope).
Pulling the plaster showed at least three vintages of plaster on
there, so I think it's an old problem with some partial repairs done
in the past.

In addition to the other comments, the flue needs ventilating top
and bottom, or it will gradually fill with condensation, which will
come through to the inside as a damp chimney stack. The vents can
both be to the outside, so you don't lose heat from the house up
the chimney.

That's what I was going to post.
The idea of the overhang is that it sheds water that might otherwise
get in from a vent. You only need an half inch or so. Take a brick off
one of the sides in the middle and replace it with two halves of a
quarry tile or something.

If you are going to the expense of scaffolding then you may as well
take the chimney down below the roof.

The cheapest bodge around the problem would be to drill a couple of
holes on the ladder side of the chimney fairly near the top. And maybe
stick a couple of plastic tubes in with a slight slope on them the
stop rain pouring in.

When you get up there, tie you ladder to the chimney and use a long
rope to haul up your drill.

In article ,
Weatherlawyer writes:
On Sep 2, 10:53*am, (Andrew Gabriel)
wrote:
In addition to the other comments, the flue needs ventilating top
and bottom, or it will gradually fill with condensation, which will
come through to the inside as a damp chimney stack. The vents can
both be to the outside, so you don't lose heat from the house up
the chimney.
That's what I was going to post.
The idea of the overhang is that it sheds water that might otherwise
get in from a vent. You only need an half inch or so. Take a brick off
one of the sides in the middle and replace it with two halves of a
quarry tile or something.

It makes sense to avoid water going in the vent, but it really
doesn't matter if it's vented. A completely uncapped flue open
to the rain which is vented will stay drier than a capped and
unvented flue.

I used a bog-standard eathernware air brick, in place of one
of the original bricks. For the lower one, I used a plastic
version which allows the grille to be unclipped for clearing
out cobwebs, etc. Also found them useful when I was installing
central heating, as that proved to be the only way to get long
lengths of copper pipe down under the ground floor.

Initially I had no access to the chimney stack above the roof,
so I took out half a brick in the loft. Some years later when
I had scaffolding up around the chimney, I fitted the air brick
properly, just below the corbeling around the top of the stack.

If you are going to the expense of scaffolding then you may as well
take the chimney down below the roof.
The cheapest bodge around the problem would be to drill a couple of
holes on the ladder side of the chimney fairly near the top. And maybe
stick a couple of plastic tubes in with a slight slope on them the
stop rain pouring in.
When you get up there, tie you ladder to the chimney and use a long
rope to haul up your drill.

I would not rest a ladder against a chimney stack in unknown
condition. When you look down the flues, you will likely see
half the mortar has been washed away over the years, and it
may be nowhere near as strong as you might imagine.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In message o.uk, Dave
Liquorice writes
On Sun, 2 Sep 2012 11:49:33 +0100, Phil L wrote:

If I do slab it, how about 1/2" cement board? (I have some, and it's
lighter)

No.
It needs to be heavy duty, if you put anything flimsy up there, the
elements will destroy it in short time or it will end up in next doors
backyard once the first gust of wind licks it

Agreed and take note of the last bit. The 3 x 2 slab on the barn stack
was moved by the wind here and it only has a small over hang for the wind
to gat hold of. It now has some large screws into the stone/brick work
below. The OP's place looks as if it might be a bit exposed to SW'ly
gales coming up the Bristol Channel.

You may need to hire a roofer and/or a cherry picker, failing that,
scaffold.

Scaffold is cheap, I got the impression from some of the other photos
that the ground sloped by the base of the relevant wall so a cherry
picker might not have suitable access and it looked quite a way up as
well, cherry pickers wobble...

Also to easily point the the new slab onto the stack you need all round
access.

The agricultural solution:-)

I just happened to have an almost big enough piece of 3mm galvanised
sheet lying about.

I had scaffolding up to re-do the lead work and pointing so access was
easy. In the event, the top few courses of brick needed relaying.

The imitation forge canopy is secured by stainless bolts to some
galvanised heavy angle fitted inside the flues.

http://s828.photobucket.com/albums/z...ew&current=MFc
himney001.jpg

regards



--
Tim Lamb

In message , Tim Lamb
writes
In message o.uk,
Dave Liquorice writes
On Sun, 2 Sep 2012 11:49:33 +0100, Phil L wrote:

If I do slab it, how about 1/2" cement board? (I have some, and it's
lighter)

No.
It needs to be heavy duty, if you put anything flimsy up there, the
elements will destroy it in short time or it will end up in next doors
backyard once the first gust of wind licks it

Agreed and take note of the last bit. The 3 x 2 slab on the barn stack
was moved by the wind here and it only has a small over hang for the wind
to gat hold of. It now has some large screws into the stone/brick work
below. The OP's place looks as if it might be a bit exposed to SW'ly
gales coming up the Bristol Channel.

You may need to hire a roofer and/or a cherry picker, failing that,
scaffold.

Scaffold is cheap, I got the impression from some of the other photos
that the ground sloped by the base of the relevant wall so a cherry
picker might not have suitable access and it looked quite a way up as
well, cherry pickers wobble...

Also to easily point the the new slab onto the stack you need all round
access.

The agricultural solution:-)

I just happened to have an almost big enough piece of 3mm galvanised
sheet lying about.

I had scaffolding up to re-do the lead work and pointing so access was
easy. In the event, the top few courses of brick needed relaying.

The imitation forge canopy is secured by stainless bolts to some
galvanised heavy angle fitted inside the flues.

http://s828.photobucket.com/albums/z...ew&current=MFc
himney001.jpg

Unhappy wrap on my display! Pasted in a browser with the gap between *c*
and *h* deleted it worked.

regards

--
Tim Lamb

Is there any black mould on the damp areas? If not then the
problem is probably acid salts that have leached through from the
flue. They will be hygroscopic hence the damp patch. The cause is
the kitchen range. Your might stop it with some sort of sealant.
One cure is acid resistant plaster.
Allan



Andy Dingley wrote:

Damp patch inboard of an outside chimney, with no obvious cause or
broken thing to fix.

Late-Victorian three storey, with an external brick chimney for the
old kitchen range.
http://quercus.livejournal.com/240103.html#cutid1
http://quercus.livejournal.com/32427...43408#t1343408
The chimney is capped at the top (paving slab), but unventilated at
the bottom. It has a lead gutter into the corner of the roof. Access
is a pain, as I don't have ladders to do it and there's also a
protruding conservatory beneath.
http://quercus.livejournal.com/324272.html