Flaunching is the mortar base holding the chimney pot in position on top of the chimney
stack. If there are minor cracks in the mortar, these are easily repaired with mastic
applied with a gun or pressed into the cracks.
Replacing the flaunching
If there are more serious cracks evident, then the flaunching should be completely
replaced. It is important to support the chimney pot before removing the flaunching. Tie
a length of rope around the top of the pot (A) and a second rope around the chimney stack (B).
Then secure by attaching a rope from A to B on both sides of the stack. This should hold
the pot in position before removing the flaunching.
Use a cold chisel and club hammer to
remove the damaged mortar. Brush away the unwanted material and dampen the surface of the
stack. This is necessary, especially in warmer weather, to stop the mortar from losing
moisture too quickly, which would result in cracking. Use mortar consisting of
approximately a 1:4 cement:sand mix to replace the flaunching around the base of the pot.
