The Basics of Plumbing

Plumbing is a trade that deals with the supply and disposal of water in buildings. It is a highly specialized field that requires skill and expertise to be performed correctly.

Plumbers install and connect pipes, faucets, and fixtures. They also inspect and repair existing systems. They must be knowledgeable about building codes and blueprints to correctly plan installations.

Water Supply

A water supply network supplies drinking and cooking water to homes and businesses. It transports raw water from a source, such as a lake or river, to a treatment plant where it is purified for consumption. The network is usually pressurised to ensure that sufficient water flows to all points in the system and that untreated water cannot enter the distribution pipes.

Water supply lines may be made from a variety of materials, including copper, steel, lead, polyvinyl chloride (PVC), and cross-linked polyethylene (PEX). PEX is the preferred option for many professionals, DIYers, and homeowners because it allows for more connections with fewer pipe joints.

Plumbing systems are designed as a closed loop to avoid dead ends, and all have valves to allow for the isolation of sections in case of contamination or other problems. This ensures that safe water can continue to be delivered even if the section in question needs to be isolated for maintenance or repair.


Drainage pipes carry waste water away from toilets, showers, sinks and washing machines. They usually run underground and are not connected to the water supply system. If they clog, you can usually fix it by pouring drain cleaner down them. If the blockage is deeper, a plumber will use specialized equipment to clear it for you.

Drains are often overlooked, but they’re crucial for maintaining a clean home. They keep waste and excess water flowing in the right direction to avoid backflow and sewage spillage.

Pipes in drainage systems are usually made from plastic (PVC or PEX), which is resistant to corrosion and abrasion. Metal pipes are occasionally used, especially for older homes, but they’re often replaced with the softer and less corrosive plastic alternatives. House drains are usually sloped toward the sewer line to allow scouring action. The typical slope is 1/4 inch per foot. These drains also tie into soil stacks, which receive the discharge from WCs and urinals.


Behind your walls and under your floors is a network of wastewater drainage pipes that drain your sinks, tubs and other fixtures. Proper plumbing venting ensures that these pipes can function properly, without backpressure and with a constant flow of fresh air. Without proper ventilation, the water may stagnate, creating foul odors and potentially toxic molds that can be dangerous to your family.

The primary function of a plumbing vent is to protect the trap seals in each drain, by balancing the air pressure inside the drainage system. Without a vent, pressure fluctuations can cause siphoning, where the atmospheric pressure on the discharge side of the trap is lower than that of the inlet. The trapped water is then sucked down the drain, along with bad-smelling sewer gases.

Plumbing vents can either be conventional, where each fixture has its own individual vent pipe (like the bathtub’s in this example) that terminates outdoors to open air, or an AAV (Air Admittance Valve), which is a one-way valve that allows air in during negative pressure and closes by gravity when positive pressure is present. Each type of venting method has its own advantages and disadvantages.


Appliances, such as washing machines and toilets, are some of the most essential parts of a plumbing system. Although these products seem like they are independent of one another, they actually have more connections than what the average person would think. In fact, all of the appliances in a home have a direct relationship to the water lines they connect to. These appliances also have a relationship to the gas lines that connect them to a stove or heater. A plumber may be needed to fix a problem with these connections. A plumber can also install new appliances if existing ones are damaged or broken. Star Plus Plumbing