Removal of Chimney Breast

Once a chimney breast has been removed, you will need to make good the floor where the chimney breast once was. If you are removing it completely, the roof will also need to be patched up Any moisture in an unventilated wall or chimney will interact with the soot remaining in the used chimney and can cause staining . If you already get rid of your gas fire you can simply bricking up and plastering the chimney breast, you’ll certainly have to remove the old back boiler and cap off the gas pipe

The question was is it necessary to remove the chimney. The answer is no, the only reason to completely remove a chimney is if it's unsafe. You may remove it if you are remodelling and have structural calculations to support it. Alternatively just have the chimney capped off and save yourself the expense.

my advice would be to remove the chimney from your roof as it will only cause you problems one day, its not a huge job to remove it and slate/tile the area in. plus its one less weak spot on your roof.

If chimney is not in use any more it must be vented/ or if possible be removed. Above roof level if you can ? This may not be possible if joint with next door . If single on its own you can. And recover roof area. thanks Regards Richard