Closing off chimney with mortar
 

Hi,

We have just finished exposing a large old kitchen fireplace from
behind
a fair quantity of plaster, bricks and various other material, and we
now
want to close off the old chimney flue so that the fireplace and
hearth are
open and cleaned.

Our neighbours upstairs has the same chimney in her kitchen and people
who lived there before her seem to have closed it off with
cement/mortar. They seem to have used a mould as the mortar is
perfectly applied. Does anyone know how this is done? I was thinking
of using MDF but eventually the dampness would go through -it's also
very dirty in there.

If anyone knows what is the best way to block it off / cement it, an
answer would be much appreciated.

Thank you

Rgards

Thierry

On 23 Aug 2004 05:53:08 -0700, (thierry)
wrote:

Hi,

We have just finished exposing a large old kitchen fireplace from
behind
a fair quantity of plaster, bricks and various other material, and we
now
want to close off the old chimney flue so that the fireplace and
hearth are
open and cleaned.

Our neighbours upstairs has the same chimney in her kitchen and people
who lived there before her seem to have closed it off with
cement/mortar. They seem to have used a mould as the mortar is
perfectly applied. Does anyone know how this is done? I was thinking
of using MDF but eventually the dampness would go through -it's also
very dirty in there.

If anyone knows what is the best way to block it off / cement it, an
answer would be much appreciated.

Thank you

Rgards

Thierry
You could use a wooden board though I would steer well clear of MDF.
Good exterior ply would be fine.

It really should be ventilated and how you achieve that is up to you.
Small holes drilled in the board is one way but will allow muck to
fall through.

The correct way is to board over completely (or cement up above a
plate for example) then install a grille or some other access just
above in the flue/chimney breast. Usually, this is considered
unsightly so is often avoided.

Be sure that the top of the flue is correctly capped to allow
ventiation without water ingress. Do not allow any roofer to just
close it off completely or you will certainly get moisture coming
through the wall of the flue elsewhere.

Hope that helps but feel free to ask further.

Rob

In article ,
(thierry) writes:
Hi,

We have just finished exposing a large old kitchen fireplace from
behind
a fair quantity of plaster, bricks and various other material, and we
now
want to close off the old chimney flue so that the fireplace and
hearth are
open and cleaned.

Our neighbours upstairs has the same chimney in her kitchen and people
who lived there before her seem to have closed it off with
cement/mortar. They seem to have used a mould as the mortar is
perfectly applied. Does anyone know how this is done? I was thinking
of using MDF but eventually the dampness would go through -it's also
very dirty in there.

If anyone knows what is the best way to block it off / cement it, an
answer would be much appreciated.

I used a piece of plasterboard stuck in place with bonding coat
plaster. I put some fibreglass loft insulation on top of it, rather
more to act as a shock absorber for any bits of debris falling
down the chimney than as insulation.

I installed an air-brick into the flue above the plasterboard.
In my case it's an outside wall, so I vented to the outside
(and into the lft at the top). Venting top and bottom is essential,
or chimney breast gets wet (which is what had happened, and caused
me to have to sort it out).

I also dropped a lighting cable down the flue from the loft, and
have installed a small light on the plasterboard to provide accent
lighting in the fireplace. Plasterboard is fitted some 6" above
the fireplace opening to make the light concealled.

--
Andrew Gabriel