I have 4 redundant chimneys that need capping.

Has anyone used the Plastic (Teracotta coloured) C-Caps or should I go for
the real teracotta ;Mushroom' vent caps

Opinions please

Thanks

Gordon

"GordyH" wrote in message
...
I have 4 redundant chimneys that need capping.

Has anyone used the Plastic (Teracotta coloured) C-Caps or should I go for
the real teracotta ;Mushroom' vent caps

Vent caps unless you have other ventilation into the rooms

In article ,
"Me Here" writes:

"GordyH" wrote in message
...
I have 4 redundant chimneys that need capping.

Has anyone used the Plastic (Teracotta coloured) C-Caps or should I go for
the real teracotta ;Mushroom' vent caps

Vent caps unless you have other ventilation into the rooms

You need vents at top and bottom of flues, to create a through draft.
If the flue is on an external wall, you can create the lower vent to
the outside, rather than into the room, and this should reduce heat
loss from the room, because you can then block off the flue from the
room.

What I've done in one case is block off the flue at the top of the
fireplace opening with a piece of plasterboard held in place with
some bonding coat plaster, and a few layers of loft insulation on
top, both as insulation, and to cushion the fall of any bits of
mortar lining which fall down inside the flue. Above this I fitted
an air brick through the back to the outside, and a vent at the top.
Back of the fireplace is then lined with celotex (it's only a half
brick wall, and would otherwise be a cold spot), and the fireplace
plastered. Makes a nice hole for the HiFi. Also got a light hidden
in the recessed top of the firplace, cable dropped down the old
flue from the loft, and fitted a socket in the side for HiFi
(avoided back, because cold spot might cause condensation in the
back of the socket eventually).

Before I did this, the fireplace had been bricked up with a vent
brick into the room for at least 20 years. The pot on the chimney
was loose, and I had it taken down and capped. Neither I nor the
person who did it realised it should have been vented. Over the
next 20 years, the flue slowly, unknown to me, filled up with
condensation, to the point where there was water permanently
dripping down it. This only came to light when I went to strip
the wall paper, found the plaster was all detached from the chimney
breast and self-supporting with the aide of the wall paper. Pulled
the plaster down to find the chimney breast soaking wet - the
separation of the plaster from it had kept the plaster dry and
hidden what was going on behind. Fitted a vent at the top and left
it all for 3 months, and it completely dried out. It's been bone
dry for the 5 years since then, with the vents at both bottom and
top. The uncapped flues are also bone dry (in spite of the rain
that must come down them), so I would say it's much more important
to keep a flue fully ventilated than it is to cap it.

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

Thanks for all your input

The C-Cap and the Mushroom both fit onto the exsisting pot but allow for
ventilation. The four pots are on a stack of 6 so I want to retain the pots
for aesthetic reasons and so will use a vent cap on the pot.

I wondered what the plastic C-Caps look like in real life, they look quite
neat in the pictures (google C-Cap)

Unfortunatly my flues are all internal so an internal vent it will have to
be at the bottom.

"Andrew Gabriel" wrote in message
...
In article ,
"Me Here" writes:

"GordyH" wrote in message
...
I have 4 redundant chimneys that need capping.

Has anyone used the Plastic (Teracotta coloured) C-Caps or should I go
for
the real teracotta ;Mushroom' vent caps

Vent caps unless you have other ventilation into the rooms

You need vents at top and bottom of flues, to create a through draft.
If the flue is on an external wall, you can create the lower vent to
the outside, rather than into the room, and this should reduce heat
loss from the room, because you can then block off the flue from the
room.

What I've done in one case is block off the flue at the top of the
fireplace opening with a piece of plasterboard held in place with
some bonding coat plaster, and a few layers of loft insulation on
top, both as insulation, and to cushion the fall of any bits of
mortar lining which fall down inside the flue. Above this I fitted
an air brick through the back to the outside, and a vent at the top.
Back of the fireplace is then lined with celotex (it's only a half
brick wall, and would otherwise be a cold spot), and the fireplace
plastered. Makes a nice hole for the HiFi. Also got a light hidden
in the recessed top of the firplace, cable dropped down the old
flue from the loft, and fitted a socket in the side for HiFi
(avoided back, because cold spot might cause condensation in the
back of the socket eventually).

Before I did this, the fireplace had been bricked up with a vent
brick into the room for at least 20 years. The pot on the chimney
was loose, and I had it taken down and capped. Neither I nor the
person who did it realised it should have been vented. Over the
next 20 years, the flue slowly, unknown to me, filled up with
condensation, to the point where there was water permanently
dripping down it. This only came to light when I went to strip
the wall paper, found the plaster was all detached from the chimney
breast and self-supporting with the aide of the wall paper. Pulled
the plaster down to find the chimney breast soaking wet - the
separation of the plaster from it had kept the plaster dry and
hidden what was going on behind. Fitted a vent at the top and left
it all for 3 months, and it completely dried out. It's been bone
dry for the 5 years since then, with the vents at both bottom and
top. The uncapped flues are also bone dry (in spite of the rain
that must come down them), so I would say it's much more important
to keep a flue fully ventilated than it is to cap it.

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

"Andrew Gabriel" wrote in message
...

Before I did this, the fireplace had been bricked up with a vent
brick into the room for at least 20 years. The pot on the chimney
was loose, and I had it taken down and capped. Neither I nor the
person who did it realised it should have been vented. Over the
next 20 years, the flue slowly, unknown to me, filled up with
condensation, to the point where there was water permanently
dripping down it.

Where was all that moisture coming from ?
I take it you capped but retained the vertical stack above the roof line, so
perhaps the rain was soaking down through the stack bricks causing the
problem. With virtually no air flow from the room into the chimney cavity
that doesn't seem a very likely source.

I too am thinking about closing off a chimney, and from what you say it
seems important to reduce the stack to below roof level and roof over. If
you had done that do you think any damp could have been avoided ?

Roger R

In article ,
"GordyH" writes:
I have 4 redundant chimneys that need capping.

Has anyone used the Plastic (Teracotta coloured) C-Caps or should I go for
the real teracotta ;Mushroom' vent caps

Opinions please

I wanted to do the same, but didn't want anything particularly obvious
when viewed from the ground. Initially I bought a couple of heavy
teracotta elephant's foot plugs to go in the top, but decided not to
use them because they look ugly (and stop all the pots on the houses
matching).

Further searching found the C-cap, and Brewers Chimney Cappers (two
fixing styles). C-cap was too small for my pots, and is still quite
visible. Brewers Chimney Cappers require either a giant jubilee clip
around the pot (yuk) or 3 wing-nuts sticking out (yuk). Anyway, decided
to get the Brewers one with the jubilee clip and see if I could mod
it to do a hidden fixing.

Anyway, that turned out to be very easy...
http://www.facebook.com/photo.php?pi...&id=1619546457
(Hum, there are two pictures, but both seem to have the same URL?)

Now, what to do with two elephants feet?

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

In article ,
(Andrew Gabriel) writes:
In article ,
"GordyH" writes:
I have 4 redundant chimneys that need capping.

Has anyone used the Plastic (Teracotta coloured) C-Caps or should I go for
the real teracotta ;Mushroom' vent caps

Opinions please

I wanted to do the same, but didn't want anything particularly obvious
when viewed from the ground. Initially I bought a couple of heavy
teracotta elephant's foot plugs to go in the top, but decided not to
use them because they look ugly (and stop all the pots on the houses
matching).

Further searching found the C-cap, and Brewers Chimney Cappers (two
fixing styles). C-cap was too small for my pots, and is still quite
visible. Brewers Chimney Cappers require either a giant jubilee clip
around the pot (yuk) or 3 wing-nuts sticking out (yuk). Anyway, decided
to get the Brewers one with the jubilee clip and see if I could mod
it to do a hidden fixing.

Anyway, that turned out to be very easy...
http://www.facebook.com/photo.php?pi...&id=1619546457
(Hum, there are two pictures, but both seem to have the same URL?)

Other one:
http://www.facebook.com/photo.php?pi...&id=1619546457

Now, what to do with two elephants feet?


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

On Sun, 11 Apr 2010 21:30:27 +0000 (UTC), Andrew Gabriel wrote:

http://www.facebook.com/photo.php?pi...&id=1619546457

I was going to ask how close to the pot they fitted. I wonder if
there will be enough ventilation. What do the destructions say about
the gap between cap and pot if using the giant jubile clip?

All the commercially avialable caps I've seen have a lot more
ventilation that what you appear to have there. Not sure I'd trust 3
bits of 2.5 twisted together copper to support a brick for years at a
time, possibly in a mildy corrosive atmosphere inside a chimney. Now
some galvanised builders band bolted to the cap bands...

I like it though we have 5 or is it 4 capped flues here and the
pottery vent caps up there ATM are pig ugly.

--
Cheers
Dave.

In article o.uk,
"Dave Liquorice" writes:
On Sun, 11 Apr 2010 21:30:27 +0000 (UTC), Andrew Gabriel wrote:

http://www.facebook.com/photo.php?pi...&id=1619546457

I was going to ask how close to the pot they fitted. I wonder if
there will be enough ventilation. What do the destructions say about
the gap between cap and pot if using the giant jubile clip?

There's between 1-2cm all around. It's a bigger gap than it would be
with the jubile clip because the straps are folded back on themselves
and the cap is sitting on them (and I bent them by hand, so it's
not a tight fold back). It's a lot more than the classic air-brick in
the side of the stack (which is what I've done for the flue which has
been flaunched over). The instructions for jubilee clip fitting say
ensure there's a 5mm gap all round.

Somewhat annoyingly, after I'd repaired the flaunching over the missing
pot and I was going around the roofing suppilers looking at caps,
I found one which had a reclaimed pot to match the missing one. If
I'd found this before repairing the flaunching, I would have fitted it
to restore the full compliment for the sake of appearances.

All the commercially avialable caps I've seen have a lot more
ventilation that what you appear to have there. Not sure I'd trust 3
bits of 2.5 twisted together copper to support a brick for years at a
time, possibly in a mildy corrosive atmosphere inside a chimney. Now
some galvanised builders band bolted to the cap bands...

I had some non-galvanised steel cable (lashing cable for aerial
chimney bracket which I didn't use in the end). I thought the copper
would last longer, and I don't expect it to be particularly corrosive
in there. Seemed like a good way to use up some red+black T&E too;-)

I like it though we have 5 or is it 4 capped flues here and the
pottery vent caps up there ATM are pig ugly.

This capper says it's designed for 5-10" pots. Mine are actually
11-12", so it's more flush fitting with the sides than they intended
it to be.

Just wondering if I take the pottery ones back (less 25% resocking
fee), or plant them out with something interesting for my nephew.
They are quite heavy (much heavier than a normal planter).

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

On Mon, 12 Apr 2010 09:34:06 +0000 (UTC), Andrew Gabriel wrote:

I was going to ask how close to the pot they fitted. I wonder if
there will be enough ventilation. What do the destructions say
about
the gap between cap and pot if using the giant jubile clip?

There's between 1-2cm all around. It's a bigger gap than it would be
with the jubile clip ...

Ah it looks a lot snugger than that in the picture, ample space.

I had some non-galvanised steel cable (lashing cable for aerial
chimney bracket which I didn't use in the end). I thought the copper
would last longer, and I don't expect it to be particularly corrosive
in there. Seemed like a good way to use up some red+black T&E too;-)

I'd expect the aerial lashing wire to be galvanised but then... Just
thinking that copper is quite soft and will stretch and thus weaken
over time, particulary at the stress points on the corners of the
brick.

--
Cheers
Dave.