What purpose do chimney pots serve?

Chimney pots serve a number of purposes and are essential for the functionality of a chimney. Usually made of clay or tin they are located on top of the chimney and help increase the speed that smoke rises by reducing the size of the outlet. This reduction in the size of the opening also reduces the threat of rain and downdrafts of air entering the chimney, which in turn aids the prevention of smoke being blown back into the building. For this reason, it is essential that the chimney pot remains in good working condition

 

Replacing Damaged Pots & Flaunching

Chimney pots do not last forever. Occasionally they will crack, this can be caused by the weather and frost, but is usually down to a chimney fire, often without the householder’s knowledge. Over time the mortar flaunching at the base of the pots can eventually start to crack and disintegrate. Despite the weight of the pots, there is a risk that storm-force weather could then displace them. This can become a problem when it comes to sweeping and it has been known for a broken pot to split apart and fall to the ground.

If you are replacing an existing, damaged or broken chimney pot you will need to completely remove what is left of the existing pot, and any mortar holding it in place.
You will need to be very careful, as chimney pots can be surprisingly heavy - many older pots were manufactured from very substantial clay and subsequently can be disarmingly heavy.
It will be a tricky job to remove the chimney and the mortar holding it in place (assuming that it is still fixed in position) and you will then need to carefully and safely get the broken pieces down to ground level.