For the most part you do not see it; think about it; or worry about it until something
goes wrong. As Murphy's Law would have it,
you most likely will have a plumbing problem some time.
Why would your sink, tub, shower or toilet drain very slowly?
There are several possibilities:
The vent system could be obstructed,
The "P" trap may be clogged,
There could be a partial obstruction in the line between the individual facility and the main drain, or
The main drain could be partially obstructed.
If only one facility does not drain:
The problem lies somewhere between the facilities and the main drain.
If more than one, but not all of the facilities, do not drain properly:
Then the problem lies somewhere within your home's internal plumbing system.
If no facilities drain properly:
The problem can be either in the main drain within the house or in the property's service connection that
connects the home to the main sewer line.
Obstructions in the property service connection can result from:
Grease buildup,
A solid object flushed into the drain line,
A caved in line,
A swag (dip) in the line that allows solids to settle out and eventually obstruct the line, or
Roots in the line that have entered at unsealed joints, slipped joints or cracks in the pipe.
What can you do to help prevent plumbing problems?
Never flush or dump solid objects, hair, cloth, grease or animal fats into your drain system.
You should not plant trees over or near the property service connection.
What steps should you take if you experience problems that you cannot take care of yourself?
goes wrong. As Murphy's Law would have it,
you most likely will have a plumbing problem some time.