Let the water flow throughout your home where you need it most
Your plumbing system consists of supply, drainage, and venting components.
The different parts of the system help keep wastewater separate from the potable supply.
The supply system relies on water pressure, whereas the drainage system works with gravity.
Many of us don’t realize the value of our plumbing system until something goes wrong—then, it quickly becomes of paramount importance. Although it operates out of sight (and oftentimes out of mind), it’s important to grasp how this system works and what kind of problems can occur. With the right base knowledge—and the expert care of a reputable plumber—you can preserve the systems that deliver water to and from your home.
Let’s take a closer look at how plumbing works in houses and the components and design principles that make up the average residential plumbing system.
Every home plumbing system has three main parts: the supply, the drainage, and the venting system. These are all vital to the safety of your water supply, as the "waste" portion has to stay separate from the "potable" supply. Otherwise, you could have a big problem on your hands. Here’s a breakdown of these important components and some plumbing basics.
The supply system uses pressure to carry water throughout your home to your kitchen sink, toilet, and wherever else you need it. This is basically a series of pipes, valves, fittings, and faucets. Separate pipes carry out cold or hot water as necessary.
Your home plumbing system relies on the natural properties of gravity and pressure. As water enters the pipes, it travels with sufficient pressure to move uphill, around pipe elbows, and so forth. The drainage system, on the other hand, depends on gravity to "flush" the wastewater out.
Cold water is always on standby and ready for use, but it goes through an extra step before you can get hot water. Cold water travels through a dedicated pipe to your gas or electric water heater, which then generates the hot water.
Speaking of water heaters—your water heater is usually the second-biggest consumer of energy in your home (second only to the HVAC system). For both traditional and tankless water heaters, proper maintenance is crucial to conserve energy. Also, if you have a natural gas water heater, make sure your local plumbing repair technician has experience with natural gas.
Rather than using pressure, drainage components rely on gravity. To encourage this process, drainage pipes follow a downward slope, which naturally guides waste to the sewage lines or septic tank. This waste then gets delivered to your home’s septic tank or public sewer system.
The venting system connects to the waste drainage piping and performs a critical role. As you’ve probably gathered, the plumbing supply and drainage systems must never mix—and the venting system prevents this from happening. Without it, the water supply would routinely get contaminated.
To prevent any disastrous commingling, the "bridges" that exist between the drain and supply systems are vented. These vents emit air into the draining pipes, which prevents the mixing of sewer gases into the drains. In effect, this vented air causes the traps in the drains to stay shut, preventing contamination of the plumbing system. If these vents get clogged, whether it’s by critters making nests or by other types of damage, it can create serious problems.
As stated before, the plumbing supply and drainage systems must be two very different operations that do not overlap. However, some bridges exist between the two, making the whole plumbing system work harmoniously. No, the Golden Gate Bridge isn’t the connecting factor between these two systems—it’s fixtures.
The term “fixture” encompasses any device that draws fresh water in and discharges wastewater while keeping the supply and drainage systems separate. Sinks, toilets, and bathtubs are fixtures, as are even things you wouldn’t think about, like washing machines. These bridges help us meet even the most basic plumbing situations and hold our home’s plumbing system together.
Your household depends on an effective plumbing system. With so much at stake, it’s important to know what’s what. Be sure to learn what type of plumbing you have in your home, as well as basic plumbing terminology for effective understanding and communication with a licensed plumber if you ever need to call one.
Even with all your new smarts, though, remember to appreciate the complexity of your home’s plumbing system. Whether you need new bathroom plumbing, a whole-house setup, or a quick repair, always leave the important stuff to your trusted local plumber. Most plumbing repair costs fall between $180 and $500 on average—a price tag that often beats the cost of replacing plumbing systems and water damage restoration costs from DIY plumbing gone wrong, which can cost upwards of $15,000 for extensive water damage.
Many problems can pop up in a plumbing system that might go unnoticed by even the most observant homeowner, making it important to schedule plumbing maintenance every one or two years. Even if you know your home’s plumbing like the back of your hand, conducting routine plumbing inspections is an absolute must for preventing leaks, extending your plumbing system’s lifespan, and catching issues as soon as they arise.
Without the trained eye of a professional, you could miss essential warning signs that your plumbing system is off-kilter, which could end up developing into a major problem by the time you detect it and lead to emergency services and paying extra for repairs. To put this into perspective, emergency plumbers cost between $60 and $600 per hour.
In a plumbing inspection, a licensed plumber will check the interior and exterior parts of your plumbing system for signs of damage and poor condition. This includes your water supply lines, sewage lines, pipes, water heater, toilet, sinks, and more. For major plumbing problems, your pro might even use a high-definition camera to scout leaks and quickly repair or replace pipes.
A plumbing inspection costs between $100 and $1,375, or around $575 on average, and can depend on the scope and condition of your plumbing system.
Heather Ayer contributed to this piece.
Most plumbing lasts anywhere from 20 to 100 years, but it depends on the type of plumbing and materials. For example, copper and cast iron pipes last between 50 and 100 years on average, while galvanized steel, PEX, and brass pipes have lifespans ranging up to 50 years. Your soil acidity and extreme temperatures both impact how long pipes last, so keep in mind your home’s climate and soil quality when determining the lifespan.
Your home’s plumbing has three types to ensure safe water usage and waste disposal. You have your drinking water plumbing system, which sends clean water to your sinks, bathtubs, and other faucets; the sewage plumbing system, which removes wastewater from sinks, bathrooms, and appliances; and the drainage system, which helps with rainwater runoff control. Each system works to keep your home dry, clean, and functional.
