What can happen?
Sewers and drains, whether private or public, are designed to deal with human waste, toilet paper, waste water and nothing else.
There are up to 200,000 sewer blockages throughout the UK every year of which 75% are caused by fat, oil and grease poured down the drain.
External drain runs.
When an external drain run is damaged, this can lead to leeching of the pipe surround, thereby increasing the problem and accelerating development as packed earth etc. is washed away.
Old joints may eventually fail over time.
Traffic movement is constantly increasing and causes ground movement.
The joints/cracks can start to open and the pipe may break as it loses support.
Roots can find their way into the pipe as gaps and cracks open up and these can then act as nets to hold on to detritus.
This reduces flow and can eventually lead to a blockage.
The roots can also grow as a mass to fill the pipe.
FOG - fats, oils and greases - are deposited in drain runs as they cool and congeal on their outward journey.
The pipe gradually becomes narrowed, increasing the chances of blockages. Over time, the fat hardens to a solid mass.
Responsible for 75% of sewer blockages.
The common physical faults are:
Displaced joint - joints opened by varying degrees due to ground movements.
Longitudinal/latitudinal cracks - cracks and fractures in the pipe.
Collapsed pipe - the pipe has broken or been crushed.
FOG - Fats, oils and grease congeal in drain runs and are a common cause of blockages. This is especially relevant to commercial or staff kitchens and other high use areas where cooking takes place.
A grease trap may help or be a requirement - see Grease Traps.
Many people still flush kitchen towels down the drain - they do not breakdown and can snag and start accumulation of matter.
Urinals need a good flow of water to carry away the uric acid. This can crystallise and over time, harden into a concrete like substance.
Foreign objects are often found having been flushed down the toilet.
Simple, but true, many pipe runs do not have the correct, if any, fall.