Basic knowledge for better decisions: Plumbing System

Homeownership comes with maintenance and repairs. Great plumbers will make it easy for you to understand what is going on with your system, but if you are acquainted with the basics, you will be able to make a smart call when opting for repairs. Below you’ll find some common terms you may hear.

DWV System: Drain, Waste, Vent System. This system carries waste out of your home and into the city sewer lines (or septic system). The most important rule for this system is that every drain must have a trap, and every trap must have a vent. Traps, those U-shaped pipes you see under sinks, hold wastewater which prevents smelly sewer gas from flowing up into your home. Vents are simply pipes that lead outside through the roof. Without a vent, water flowing through a trap creates a vacuum and siphons the trap dry. By allowing air into the system, vents act as a vacuum breaker.

Water Supply System: Your water supply system taps into the city water main, runs through a meter that measures your water usage and then branches throughout your home. If you have a well, it taps into the pipes directly. Branch lines in a home may be made of a variety of materials (see below). The older the home, the more common it is to see a variety of pipe material types.

“Aggressive” water: Aggressive water is water that is prone to corrode pipes. When pipes corrode, leaks can develop and structural damage is possible. Certain pipe materials are affected more than others.

AAV: Air admittance valves. An air admittance valve lets air into (but not out of) the DWV system. Because of this, it can take the place of a vent pipe running up through the roof. On remodeling projects, utilizing air admittance valves can save the plumber a lot of work- and you a lot of money- if it is allowed by your local code. AAVs are not allowed in all situations.

Most common distribution pipe materials:

Galvanized Steel: Unlike other types of pipe, galvanized steel almost always has threaded, screw-together connections. Its life expectancy is about 70 years, but some century old galvanized pipes are still in service. If you have galvanized pipe and low flow at faucets, chances are the pipe is to blame. Galvanized pipe is prone to mineral buildup that eventually chokes off the water flow. Complete replacement is the best cure, but you can often improve flow just by replacing any exposed horizontal pipes.

Copper Pipe: Copper was the standard water supply pipe for decades until less costly materials became available. It can be connected in several ways, but most joints are sealed by melting metal solder into the joint. The lifespan of copper depends on the local water. In some areas, it lasts as little as 25years. In others, it lasts 2-3 times that long.

PEX: PEX is flexible, so it’s much easier to install than other types of pipe. That, plus low cost and immunity to aggressive water, make it the most common choice for newer waterlines. PEX is a latecomer to North America, but has been used for decades in Europe. PEX comes in a variety of colors.

CPVC: Unlike metals, this plastic pipe doesn’t corrode, so it’s been common in regions with “aggressive” water for the past 40 years. CPVC connections are usually made with a glue-like cement, but compression fittings and other methods can also be used.

PB: Polybutylene pipe. Polybutylene is a form of plastic resin that was used extensively in the manufacture of water supply piping from 1978 until 1995. Due to the low cost of the material and ease of installation, polybutylene piping systems were viewed as “the pipe of the future” and were used as a substitute for traditional copper piping. While scientific evidence is scarce, it is believed that oxidants in the public water supplies, such as chlorine, react with the polybutylene piping and acetal fittings causing them to scale and flake and become brittle. Micro-fractures result, and the basic structural integrity of the system is reduced. Thus, the system becomes weak and may fail without warning causing damage to the building structure and personal property. It is believed that other factors may also contribute to the failure of polybutylene systems, such as improper installation, but it is virtually impossible to detect installation problems throughout an entire system. Throughout the 1980’s lawsuits were filed complaining of allegedly defective manufacturing and defective installation causing hundreds of millions of dollars in damages. Although the manufacturers have never admitted that poly is defective, they have agreed to fund the Class Action settlement with an initial and minimum amount of $950 million. You’ll have to contact the appropriate settlement claim company to find out if you qualify under this settlement- but to our knowledge, payouts have ended.

Also check out a prior blog about pouring grease down the drain, located here, or another one on low water pressure, found here, for further practical tips and info related to your plumbing system.

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