My house was built circa 1901 and has two chimney breasts. Presumably,
each would have originally had an open fire on the ground level and a
further one on the first floor (one of which on the ground floor is
still in operation). In the attic, these two breasts meet from either
side of the house before exiting through the roof.


The fireplace which is still in use exits through one of the four
chimney pots.


Having read lots of suggestions, I had decided to place one air
brick (well, technically not an airbrick but a bunch of holes drilled
through the brick with a vent in front) in the bricked up chimney
breast on the ground floor. A second air brick would be placed directly

above it in the attic.


....and now my problem:


....how can I tell whether there is simply one cavity in the chimney
breast
between the ground floor, first floor and attic meaning placement of
the vents is not critical; or two separate cavities meaning that the
attic air brick may simply ventilate the first floor flue but not the
ground floor if not placed correctly?


I have trawled the Internet for this information but have not been able

to answer my own question...are all chimneys representative of the
Santa type - whereby a fat drunk in a red suit can simply drop down a
single cavity to deliver presents!

wrote:

The fireplace which is still in use exits through one of the four
chimney pots.
..............
...how can I tell whether there is simply one cavity in the chimney
breast
between the ground floor, first floor and attic meaning placement of
the vents is not critical; or two separate cavities meaning that the
attic air brick may simply ventilate the first floor flue but not the
ground floor if not placed correctly?

If you have four chimney pots, it would be unlikely that you don't have
four flues.

If you have four chimney pots, it would be unlikely that you don't have
four flues.

Sorry to be a bit of a muppet here but how do I fit air bricks then to
ensure the air flows through the height of the house? Can I simply fit
them both 20cm in from the left of the chimney breast and assume that
will allow movement of air between the floors and the chimney?

nonymouse wrote:
If you have four chimney pots, it would be unlikely that you don't have
four flues.

Sorry to be a bit of a muppet here but how do I fit air bricks then to
ensure the air flows through the height of the house? Can I simply fit
them both 20cm in from the left of the chimney breast and assume that
will allow movement of air between the floors and the chimney?


You just want to put them where the old fireplace would have been,
wherever that was. Not necessarily central on the chimney breast if
there are several chimneys and back to back like yours. Put it low
down, but not as low as the one I've just had to reposition when
refurbing a room recently: the old grille was completely occluded by
soot and debris which had fallen down the chimney!

David

"Lobster" wrote in message
...
nonymouse wrote:
If you have four chimney pots, it would be unlikely that you don't
have
four flues.

Sorry to be a bit of a muppet here but how do I fit air bricks then
to
ensure the air flows through the height of the house? Can I simply
fit
them both 20cm in from the left of the chimney breast and assume that
will allow movement of air between the floors and the chimney?


You just want to put them where the old fireplace would have been,
wherever that was. Not necessarily central on the chimney breast if
there are several chimneys and back to back like yours. Put it low
down, but not as low as the one I've just had to reposition when
refurbing a room recently: the old grille was completely occluded by
soot and debris which had fallen down the chimney!

And had anything adverse happened as a result of this?

I'm not convinced that providing a means for expensively-heated, warm,
moist air to travel to a point where it can reach a cooler surface,
probably covered in partly-soluble combustion by-products from years
before, on which it may deposit some of that moisture, is entirely a
Good Thing.

If you can ventilate the stack from the outside, or even from under a
suspended floor, then it may be a different matter, but otherwise I'd
just consider capping the relevant pot with a vented cap.


--
Kevin Poole
**Use current month and year to reply (e.g. )***

Put it low
down, but not as low as the one I've just had to reposition when
refurbing a room recently: the old grille was completely occluded by
soot and debris which had fallen down the chimney!


.... i was going to place them just above skirting board level.

If you can ventilate the stack from the outside, or even from under a
suspended floor, then it may be a different matter,

....no can do...exterior wall ajoins neighbours garage

but otherwise I'd
just consider capping the relevant pot with a vented cap.

....i had thought of taking no action other than capping. However, many
houses I've seen where the old fireplace has been bricked up seem to
have employed an air brick at some point.

You just want to put them where the old fireplace would have been,
wherever that was. Not necessarily central on the chimney breast if
there are several chimneys and back to back like yours.

I'm not sure what you mean by back to back? I was hoping to avoid
placing an air brick on the first floor. Also, the problem still
remains with the air brick in the attic; potentially there are two
channels behind it - would that mean two air bricks are required and
then a degree of guess work when fitting to ensure that they each
perforate one of the channels behind?

I'm not sure what you mean by back to back? I was hoping to avoid
placing an air brick on the first floor. Also, the problem still
remains with the air brick in the attic; potentially there are two
channels behind it - would that mean two air bricks are required and
then a degree of guess work when fitting to ensure that they each
perforate one of the channels behind?

I would put a vent in the wall where the fireplace opening used to be,
and then put a ventilated cap on the chimney pot.

Don't faff around putting air bricks in the loft.

Sorry to be a bit of a muppet here but how do I fit air bricks then to
ensure the air flows through the height of the house?

You either fit one air brick per flue, or you knock a gap between the flues,
so that one air brick will cover both. It is better to ventilate to the
outside than to the inside of the house, as it looks neater and is more
energy efficient.

Christian.

I would put a vent in the wall where the fireplace opening used to be,
and then put a ventilated cap on the chimney pot.

Don't faff around putting air bricks in the loft.

You either fit one air brick per flue, or you knock a gap between the flues,
so that one air brick will cover both. It is better to ventilate to the
outside than to the inside of the house, as it looks neater and is more
energy efficient.

Thanks Christian. Ideally I would like to fit one air brick per flue
but finding exactly where the flues run when the chimney breast is 5ft
across isn't easy.

Thanks to all who posted. Have decided to fit one on the ground floor
and one on the first floor fairly central on the chimney breast (and
hope for the best!)

Autolycus wrote:

"Lobster" wrote in message
...
nonymouse wrote:
If you have four chimney pots, it would be unlikely that you don't have
four flues.

Sorry to be a bit of a muppet here but how do I fit air bricks then to
ensure the air flows through the height of the house? Can I simply fit
them both 20cm in from the left of the chimney breast and assume that
will allow movement of air between the floors and the chimney?


You just want to put them where the old fireplace would have been,
wherever that was. Not necessarily central on the chimney breast if
there are several chimneys and back to back like yours. Put it low
down, but not as low as the one I've just had to reposition when
refurbing a room recently: the old grille was completely occluded by
soot and debris which had fallen down the chimney!

And had anything adverse happened as a result of this?

There is a bit of damp on the chimney breast at ceiling level, which may
or may not be penetrating rather than due to damp from within

If you can ventilate the stack from the outside, or even from under a
suspended floor,

In my case the chimney's on a party wall, but otherwise I'd agree: but
under the suspended floor? That would mean excavating out the
fireplace, and there'd still be the falling-debris issue I experienced.

David

nonymouse wrote:
I would put a vent in the wall where the fireplace opening used to be,
and then put a ventilated cap on the chimney pot.

Don't faff around putting air bricks in the loft.

You either fit one air brick per flue, or you knock a gap between the flues,
so that one air brick will cover both. It is better to ventilate to the
outside than to the inside of the house, as it looks neater and is more
energy efficient.

Thanks Christian. Ideally I would like to fit one air brick per flue
but finding exactly where the flues run when the chimney breast is 5ft
across isn't easy.

Thanks to all who posted. Have decided to fit one on the ground floor
and one on the first floor fairly central on the chimney breast (and
hope for the best!)

You really need to find where the fireplace was; if you have four stacks
together then I'd be pretty sure the fireplace in each room will be
offset from the centre, so the 'middle' would NOT be the place to go!!

Is there really no evidence as to where the old fireplaces were?
Imperfections in the plaster? renewed section of skirting board over the
fireplace? Different sounds when tapping the front? Locate any metal
lintel using a detector? If you're really stuck, try lifting the floor
coverng: I'll bet there wil be evidence of where the hearth was. An
bear in mind if you can find where the opening is in room A, then in the
adjacent room B the opening will be on the other side of the chimney breast.

David

nonymouse wrote:
I would put a vent in the wall where the fireplace opening used to be,
and then put a ventilated cap on the chimney pot.

Don't faff around putting air bricks in the loft.

You either fit one air brick per flue, or you knock a gap between the flues,
so that one air brick will cover both. It is better to ventilate to the
outside than to the inside of the house, as it looks neater and is more
energy efficient.

Thanks Christian. Ideally I would like to fit one air brick per flue
but finding exactly where the flues run when the chimney breast is 5ft
across isn't easy.

Thanks to all who posted. Have decided to fit one on the ground floor
and one on the first floor fairly central on the chimney breast (and
hope for the best!)

You could hang a length of cable or push a metal rod down the chimney
from the top and then use a cable/metal detector device to locate it
from
the outside or inside walls. There are cheap devices on the market that
should
work, although I don't know if they can detect non-live cable.

Worth a look though.

HTH
deano.

You really need to find where the fireplace was; if you have four stacks
together then I'd be pretty sure the fireplace in each room will be
offset from the centre, so the 'middle' would NOT be the place to go!!

...try lifting the floor
coverng: I'll bet there wil be evidence of where the hearth was.

BINGO! Found a slab of concrete about the width of the chimney breast
in the first floor room.

....bear in mind if you can find where the opening is in room A, then in
the
adjacent room B the opening will be on the other side of the chimney
breast.

....not sure I follow this. The chimney breasts are all at the end of
the house on the end wall - two at the front and two at the rear (it's
kinda sideways on)

You could hang a length of cable or push a metal rod down the chimney
from the top and then use a cable/metal detector device to locate it
from
the outside or inside walls.

I'd have to be spiderman to attempt this. The house is 35 ft tall and
accessing the chimney involves scaffolding - lots of it.

And I thought this would be a fairly simple job - I can't believe it's
not as simple as drilling a few holes in the wall!!!!

You could hang a length of cable or push a metal rod down the chimney
from the top and then use a cable/metal detector device to locate it
from
the outside or inside walls.

I'd have to be spiderman to attempt this. The house is 35 ft tall and
accessing the chimney involves scaffolding - lots of it.

And I thought this would be a fairly simple job - I can't believe it's
not as simple as drilling a few holes in the wall!!!!

Ok, if you can't get onto the roof, then just go into your loft, get to
where the
chimney stack comes down (probably branches off into two flues) drill a
hole
into that and feed in a length of electrical cablle. put it in a few
feet and then test
below the entry hole to see if you can pick it up with a detector, then
keep going
down with it, testing every now and then to keep track of it.