Diarmuid
Super Anarchist
But if the mortar is too degraded, or rain water has got at the bricks & liner, or there was ground settling or a wee earthquake, or someone did a hack job punching in a woodstove fifty years ago.... Even a hard whack with a sledge on the roof can cause the chimney to buckle and blow out between floors, possibly taking a good chunk of your house with it. It's a good idea to at least have a gander at the brickwork at each level before starting the demo. There's so.much.weight involved.