I have a detached house with a chimney dead centre of the property to originally serve a bolier in the kitchen. As I have a new gas boiler now on an outside wall in the Kitchen I am using the old boiler alcove as an extra kitchen cupboard and have filled in the hole in the ceiling of the cupboard where the flue went up. I have also had the chimney taken down off the roof. I am now attacking the chimney that goes through the loft space I want to get it down to under the level of the floor boarding in the loft that rests on 4"x2" joists. My plan was to cement a thick flag stone over the chimney hole level with the floor boarding in the loft to make it safe and level. Now you have the background my question - is it necessary to have an air brick in the remaining chimney wall in the loft before I cap it off under the flag stone. The chimney now is about 8' 8" long with none of its sides on outside walls. What do you experts think please
If you have taken the chimney down to below roof level then no, the air brick is to let fumes from the old burnt sut out the top. If you are taking the chimney down there is no need to vent it!