Closing and opening an existing fireplace
A fireplace, which is not used anymore, can be successfully closed to allow
more wall space…
The insertion of an air-brick is required in the closing of the fireplace to allow
air to circulate between the room and the top of the chimney, via the flue and
fireplace. This will stop moisture collecting in the soot and smoke deposits
within them and forming damp areas.
It is also advisable to cap the chimney with a ventilated cowl, which will
allow air in and out, but not water. We are working with
www.chimneycap.co.uk who produce just such a vent. The advantage of
C-cap is that it will not leak, and it can be fitted in seconds. Your
chimney is protected from the elements and from nesting
birds...Chimney Caps ventilated cowls will not leak and blend in with the
pots to maintain the traditional appearance of the stack.
First measure the opening in square metres and multiply by 60. This will tell
you how many bricks you will need. (An average fireplace will measure
approx 400mm x 550mm or 0.4m x 0.55m…. Equalling 0.22 sq. m. x 60 = 13
bricks) you will need one 9 inch x 3 inch air- brick. Common bricks can be
used for building, as they are the cheapest.
Sand and cement is obviously needed and this should be mixed at 4 sand to 1
cement for building the brickwork…The same mortar can be used for the
render to cover the bricks with later, but you will have to wet it down a little to
For an average fireplace you will also need 2 “frame cramps” which are
normally fixed to a door or window frame and built into the brickwork joints.
These 2 however, will be plugged and screwed to the inside of the fireplace
and be built into brickwork you are building. (See diagram)
The brickwork can now be built into the opening; it should be set back half an
inch from the existing face of the plasterwork surrounding the fireplace. The
air-brick however should be built out a little so that its f