A home’s plumbing system includes the water supply lines, drains, and vent pipes that bring water in and waste out. It also consists of the fixtures and equipment used with these elements.

The housing inspector must be familiar with these systems to assess their general condition and recognize inadequacies that require addressing as part of the inspection. 


Water Supply

A water supply system consists of the source of supply, the treatment or processing of the water, and its distribution to users. Usually, the head of the collection is a stream, river, lake, reservoir, or ocean.

The treatment or processing is usually done at a plant near the source. The treated or finished water is transported via conduits or pipes to a distribution system.

Flow in distribution systems may be controlled by gravity or by pressure (pumping). In gravity systems, water is impounded at strategic locations sufficiently elevated to create the working pressure required for transport to points of demand.


The drainage features of plumbing Seattle are used to keeping your home’s water clean and free from contaminants. It also helps prevent flooding and structural damage.

Drainage pipes run from your sinks and toilets to a sewer line, where the waste is then sent down to a sewage treatment facility or septic tank. These systems work by gravity, so you don’t have to worry about pressure as your drain pipes angle downward toward the sewer.

Another type of drainage is surface drainage, which removes excess water from the ground. It can be done with shallow ditches that discharge into more extensive and deeper collector drains.


Pipes are a crucial part of plumbing, as they transport water and waste from one point to another. They come in many materials, so knowing which suits your home is essential.

Usually, pipes are made of steel or iron (for example, galvanized steel, black (lacquer) steel, stainless steel, copper, and ductile iron). The type of material depends on the intended use.

Steel pipes are typically designated by their outside diameter and wall thickness in inches or millimeters, called schedule numbers. Several schedules are used in industrial and municipal piping.


Plumbing fixtures are parts of a plumbing system that serve a specific purpose. They include faucets, sinks, showers, and toilets.

They are used to distribute water and remove wastewater in buildings. They are also essential in ensuring that buildings stay hygienic and safe for people.

Various materials, such as metal, ceramic, glass, and plastic, can create fixtures. They also come in different sizes and shapes.

Each fixture drain must be vented to prevent negative air pressure in the drain from siphoning the trap dry and to stop gases from pushing past the water barrier due to positive air pressure in the sewer. They must also be sized to reduce the risk of explosive sewer gas buildup.

Plumbing Company

A plumbing company should provide a range of services to meet the needs of homeowners. These include repairs and installation of water heaters, pipes, and sewers/drains.

When launching a new plumbing business, building a solid network of contacts is essential to help you grow your client base. 

It’s also a good idea to offer membership plans that allow customers to enroll in annual inspections and follow-up calls on unsold work. These can be a great way to boost customer retention and generate income during slow times.