Gullies are a common source of blockages.
If the blockage is in the trap, it is quite easy to clear
from the gully. If the trap is clear, try pushing a rod
up the inlet of the inspection chamber in the direction
of the gully. If the gully is very deep, try plunging. The
surface of the gully should be covered completely. Use a
mop head or rags wrapped in an old towel attached to a length
of wood to tightly pack the surface creating as much pressure
as possible when you start plunging.
When clear, rinse the gully with a hose and sprinkle disinfectant
to cleanse the system. Sink waste is often contaminated
with grease and when the gully is blocked use boiling water
and a rod to disperse the blockage. If a rod isn't available
try using a wire coat hanger to help dislodge the fat.
If the area is still too difficult to clear, try using
a solution of caustic soda, being careful to follow the
instructions on the packet carefully.
