If the fireplace is never used, it may be advisable to cover
it and seal off completely. It is necessary to fit a 'hit and
miss' ventilator to provide ventilation for the flue.
If you want to keep the appearance of an open fireplace, but
do not intend to light a fire - use a sheet of thick polystyrene
to seal the base of the hole above the fireplace.
You must make a small hole, about 50mm (2 inches) in the sheet, in order to
allow for ventilation in the room. If you decide to use the
fireplace again, you must remove the polystyrene sheet beforehand.
NB: Remember, polystyrene is a flammable material
