Time to use your TV announcer voice . . .
In previous Plumbing 101 posts . . .
Decatur or Hartselle, AL, residents were given a quick, accessible understanding of residential plumbing so they know what’s going on behind the scenes in their kitchens, bathrooms, and laundry rooms.
In the last episode of Plumbing 101 . . .
Decatur or Hartselle, AL, residents were presented with a list of commonly-used plumbing terms, which could come in handy when trying to solve plumbing problems, making repairs, or simply talking with professionals about inspections, repairs, or renovations.
Tonight on Plumbing 101 . . .
The first of several deep-dive, slightly-more-comprehensive-but-still-accessible posts about residential plumbing, beginning with the drain-waste-vent system, soil stacks, traps, water supplies, and pipes.
TV announcer voice fades away.
The Drain-Waste-Vent System
As a quick reminder, the plumbing system in your Decatur or Hartselle home is composed of two separate subsystems:
- One brings freshwater in.
- The other takes wastewater out.
- Along the way there are essential components like vents, traps, and clean-outs. There’s also infrastructure like different kinds of pipes, fittings, and adhesive. Taken together, they add up to the drain-waste-vent system.
To start we’ll look at components in the drain-waste-vent system.
The soil stack is the main component of the waste drain.
The soil stack is a vertical “stack” of pipes that starts in the basement/crawlspace floor or wall where it’s connected to the outbound sewer/septic line.
The top end of the stack acts as a vent. It extends vertically out through the roof, allowing gases to escape outside and help promote drain flow by drawing air inward.
Note to homeowners: A plugged vent can trap dangerous gases and inhibit drainage. Most homeowners will not want to deal with plugged vents, particularly since they are on roofs, and may prefer to call a Decatur or Hartselle, AL-area plumber or plumbing contractor for inspection and/or repair.
FYI: A vent stack should not terminate in the attic, but it does happen. Builders take shortcuts and vent plumbing into the attic. Trapped sewer gases can be dangerous, stink, and cause serious structural problems, depending on circumstances. A system without proper venting may actually suck water out of a sink’s trap, or do the reverse and fill the sink with water when another fixture drains.
A trap blocks sewer/septic gases. Without one, sewer gases can travel the stack and come out wherever there’s a drain. At a minimum, there’s a noticeable stink.
A trap looks like a “U” and is installed below the drain, often in a cabinet under a sink, for example. When water drains, the trap’s shape causes a small amount of water to remain in the bend and that water blocks any gasses from entering the room.
Traps are needed on all drains, even if you don’t think so. Toilets, for example, have a built-in trap and do not require a separate trap in the drain line. Shower and tub traps are usually not as accessible as sink traps.
Water Supply System
Now for the system that brings fresh water into the home.
Your home’s water supply may come from a private well or a service pipe that connects to Decatur or Hartselle’s water main.
A house with a private well utilizes a pump to push water up into a pressure tank where it is stored for use. When the tank empties, the pump is reactivated to fill the tank.
A house with city water has a “live” water supply line that’s connected to a water main and meter. The meter is usually the dividing point between the city-owned lines and the homeowner’s lines.
Both systems usually have a 1/2″ or larger copper pipe that enters through the basement floor (if applicable) or wall. There is a shut-off valve located near the beginning of the incoming water line so the supply can be stopped in case of an emergency or repair.
Note to homeowners: Learn where the water main is and how to shut it off. If you are uncertain, the next time you call a Decatur or Hartselle, AL plumber for repair, get him to show you where it is located and what’s required to shut it off. This is important. If a pipe bursts, it can quickly flood your house and cost thousands of dollars in additional expense.
If the emergency is confined to a sink, tub, or toilet, you may not need to turn off the home’s entire water supply. Just turn off the individual stop valves, always located near the fixture — to the left of a toilet or under the sink.
Water supply lines are made of copper, CPVC (chlorinated polyvinyl chloride) plastic, or in older homes possibly galvanized steel.
Cold water lines branch out from the main pipe, while hot water lines originate from the hot water heater.
Codes vary and certain areas may not allow plastic pipe to be used. If you are making any changes to your home’s plumbing system, make sure you — or the plumber or plumbing contractor you hire — check with Decatur or Hartselle building authorities to find out about city codes, permits, and inspections. Doing work without a permit is illegal and may also invalidate homeowner’s insurance.￼
Several types of pipe are used in residential plumbing. These include:
- Rigid plastic PVC (polyvinyl chloride) and ABS (acrylonitrile butadiene styrene). These are the most popular types of plastic plumbing pipe. PVC is usually white or cream colored (for fresh water) and ABS is black or gray (for waste or gray water). Both are typically used only for vents and drains and aren’t made to fit directly together.
- CPVC (chlorinated polyvinyl chloride) is another rigid plastic used for hot and cold water supply lines because it can handle normal water pressure loads. Compared to copper lines, CPVC is lightweight, easy to work with, doesn’t corrode and is usually cheaper.
- Copper tubing has been a longtime standard in plumbing and requires a certain skill set for sweating (soldering) pipes and fittings together. Homeowners can do this job themselves, or have a Decatur or Hartselle, AL plumber or plumbing contractor do it. Copper is ideal for plumbing because it creates a biostatic atmosphere that makes it difficult for bacteria to grow inside. It also resists corrosion and is unaffected by ultraviolet rays, so it can be used outdoors. Its biggest disadvantage is cost.
- PEX (cross linked polyethylene) was first used in the U.S. around 1980 for radiant heat flooring applications, but it is now commonplace for re-piping (updating) and plumbing repairs. It’s popular due to cost, flexibility, resistance to scale and chlorine, fast installation with fewer connections and fittings, and it doesn’t lose heat like copper. It’s not suitable for outdoor use. It can be color coded — red for hot, blue for cold, white for any use.
Older homes generally have had cast iron pipe sealed with lead solder. However, in some of today’s homes, they may utilize cast iron pipe sealed with neoprene to avoid the noise plastic creates when water is draining.
Fitting plastic pipe and sweating copper water lines.