Sometimes you will need to remove old flaunching and reset a chimney pot if the flaunching on its base has become worn or if the pot itself is loose or damaged. If you are fitting a new pot you will similarly have to apply new mortar and flaunching.
The first step is to hack away the old flaunching, and take care here not to damage the pot if you intend to reuse it. It is often the case that the flue of the chimney is wider than the diameter of the pot, and in that case the pot is supported on strips of slate laid down around the edge of the flue.
Tie the pot to the chimney using rope to prevent it from falling into the flue as you remove the flaunching.
When you are finished, repair damaged brickwork around the top of the chimney before replacing the pot and flaunching.
It is important when working on any aspect of the roof to take safety precautions. You can erect a safe working platform from access tower components fitted with wooden boards to spread the weight on the roof.
Use a cold chisel and club hammer to remove the old flaunching and collect the pieces in a bucket rather than tossing them to the ground.
To help the new mortar adhere properly, moisten around the base of the pot with water and make the new mortar with sharp sand and a PVA additive.