Plumbing System photos: P 49-P 56
The basic operation of a plumbing system is this:
The water enters the house through the water main pipe from the city water main in the street. If the house has an on-site well, then the water main pipe comes from the well.
From this main pipe, the water is then carried to different parts of the house by the supply water pipes. Supply pipes branch out in different directions to bring the water to the faucets.
After the water is used at a faucet or shower it goes into the drain. This dirty water is carried back by drainage branch lines to a main drainage line.
The main drainage line then carries the dirty water to the municipal sewer system in the street. If the house has a septic system, the dirty water is carried to an on-site septic system for disposal.
Look at all visible plumbing lines. There will be very little to view in a finished basement or behind walls and ceilings. Check for any corrosion, leaks or for any buildup of mineral deposits. Often you'll see water stains on some of the floor joists, which are the beams that support the floor above. You'll also see water stains on the sub flooring, which is the base for the floor above. Minor water stains are normal, especially underneath kitchens and baths. You need to be concerned about extensive water damage. If any doubts exist, check the floor above the damaged or stained areas. Try bouncing on the floor above during your interior inspection to make sure that it's solid and doesn't have a spongy feel.
There are two sets of plumbing lines:
One type is the Supply lines which are the thinner lines. They're about one inch or less in diameter. Water in the supply lines is under pressure.
The other type is the Drainage and Vent lines, which are about 3-6 inches in diameter. Water in the drainage lines is not under pressure because it's for drainage. The water in these pipes flows by gravity instead of pressure.
The vents in a plumbing system are used to allow air from the exterior to enter the plumbing drainage system. They usually protrude through the roof top by one foot. Sometimes on older houses or commercial buildings you will see a goose neck vent pipe on the sidewalk in front of the property. Vent pipes keep the pressure in the drainage lines equal to the atmospheric pressure of outside air. Atmospheric pressure is the normal air pressure outside the house. The reason for this is so the plumbing lines drain properly. Improper air pressure in these lines will cause a gurgling sound in the sink and tub drains. This gurgling sound indicates that the water isn't draining properly.
The "U" under the sinks is designed to trap water so that the sewer gases don't follow the drainage lines back into the house. There should also be a "U" installed on the main drainage line. It should be near the point where the main drain line goes through the foundation wall and out into the street. Sometimes this "U " is not installed or not visible. If the plumbing lines don't drain properly, then the water in the "U " trap can be drawn out. The water is drawn out by the suction of the draining water. If this happens, there will be nothing to stop the sewer smell from entering the house through the sink drains. The "U" is not installed to catch jewelry and other objects that are dropped down the sink drain; contrary to what some people might think.
You'll also find what are called clean out plugs in the main drainage lines. These are metal screw-in type caps that a licensed plumber can remove to "snake" out the drainage lines, in case the lines get clogged. They allow convenient access to some areas that are most susceptible to clogged pipes. The clean out plugs should not be left open since the sewer lines could backup and drain into the house through the open caps.
Sometimes the homeowner will use some liquid drain clearing products that are sold in stores. These products are not recommended to be used too often. Drain clearing products have acids in them that eat away the built-up materials that are clogging the drain. However, they will also eat away the drainage lines if they're used too often. If these products are only used occasionally, it's not a problem. But if a house is susceptible to frequent drain clogging, then a plunger should be used or a licensed plumber should snake out the lines to clear them.
There are several types of plumbing line materials which include Copper, Brass, Galvanized Iron, Lead, PVC, and Cast Iron:
Copper piping is found in newer construction and in renovated older properties. Copper has a light brown color and it'll turn green or dark as it ages. The joints of copper pipes are soldered. This makes it easier to identify when it has aged.
Brass and Galvanized Iron piping are found in older construction. Brass has a yellowish or gold color. Brass is no longer used since it's too expensive and will have some lead in it. Galvanized Iron pipe has a tin or tarnished color and will attract a magnet. The joints for both of these types of pipes have threads to screw the sections together. Brass and Galvanized Iron piping tend to corrode and clog after about 30 years. It's similar to how a human artery clogs over time. If the amount of minerals in the water supply of the area is too high or too low, then these lines will clog even faster.
Lead piping is very rarely found in my area. It's not used any longer because the lead content can seep into the water supply which is very hazardous. These pipes will always leak some amount of lead content into the house water supply. A lead main entry line will be silver in color and may have a small bubble-type bulge in the beginning of the line. This bulge is known as a "wiped" joint. The name comes from melting the lead on top of the brass pipe to connect them. Then the plumber will wipe the joint with a rag. If you find lead piping or are unsure if there is any, highly recommend that the client have a laboratory water analysis done. All lead pipes should be replaced with new pipes for safety.
PVC piping, which is a plastic material, is found in newer construction drainage lines and in the drainage lines of renovated older houses. PVC has a white or black color with letter markings on the sides. The joints are slip-on sections that have an adhesive to hold them together. It's used only for drainage lines and is a noncorrosive, lightweight and easy to install piping material. Some local plumbing codes do not allow the use of PVC piping. The main drawback to PVC pipes is that a poisonous carbon monoxide gas is created if there is a fire.
Cast Iron piping is found in older construction drainage lines. Cast Iron should be painted or it'll get rusty. The joints are slip-on sections with an adhesive and sealing material called "Oakum." Sometimes the Oakum is visible as a dark colored glue around the top of the pipe joints.
There shouldn't be any mixed-material pipes that are connected to each other in the supply lines. The different types of metals can cause a galvanic action when water runs through them. This accelerates the corrosion of the plumbing lines at the point where the two different metals meet. There are special plumbing tapes, joints and chemicals on the market that are used to help prevent this corrosion problem.
Check the water main line where it enters the house. The water main for a house connected to a city water system is usually located in the lower level at the base of the foundation wall facing the street. The water main for a house connected to an on-site well water system is usually located in the lower level at the base of any of the foundation walls. Ask the owner or Realtor if you can't find the main water line. Sometimes they're behind finished walls or personal items in the lower level.
Also, recommend that all lead piping be replaced with a new pipe for safety. The reason for this is that lead poisoning is the NUMBER ONE childhood disease in the USA.
Find out what type of pipe material the main water line is made of. Usually it'll be copper for a house with city water and it may be plastic for a house with well water. As I said before, if you see a lead main water line or any lead piping in the house, highly recommend that the client have a laboratory water analysis done for safety. Also, recommend that all lead piping be replaced with a new pipe for safety. The reason for this is that lead poisoning is the NUMBER ONE childhood disease in the USA. Lead is an element that doesn't break down when it gets in your system. The effects of lead poisoning in children are irreversible!! Lead poisoning can damage the kidneys, nervous system and blood, and can cause permanent brain damage. So don't take any chances with this stuff.
Lead solder can no longer be used in the plumbing pipes leading to drinking water. Solder is the metal used to weld the joints of metal pipes together. I don't believe that lead solder should be used on any pipes! Let's say a plumber is working at a house and he runs out of non-lead solder. As a result, he's only left with lead solder. What are the chances of that guy stopping what he's doing to go buy more non-lead solder? I've found many contractors don't even like to file building permits and approvals for the work they do. They don't want to do the extra work and so they never mention the need for permits to the homeowner. People like that ignore the safety concern and the law by rationalizing away the necessity for building department permits and approvals. Do you really think that they're going to care about a few lead soldered joints in contact with your drinking water?
In older houses there will be lead in some of the soldered pipe joints. Gradually, over time the amount of lead in the solder will be reduced from leaching into the drinking water. The amount of lead that leaches into the water from the solder depends upon several factors. One is the quality of the water. Meaning, if the water has a high acid content, because of a low mineral problem, then more lead will leach into the drinking water. The other factor is how long the water sits in the pipes with the lead solder. The longer the water faucet isn't turned on, the longer the water will remain in the pipe absorbing the lead. Because of this, ice makers are prone to very high lead levels. The water in a freezer ice maker can sit in the pipe for days. This allows enough time for the lead to leach into the water at high levels. A lead abatement contractor told me that he's tested houses where the children had extremely high levels of lead in their bodies. He said that after the test results came back, almost all the lead in their bodies was coming from the ice cubes!
I hate to tell you, but it gets even worse. Brass or bronze plumbing fixtures and valves can leak lead into the water. The reason for this is that lead is used to fill the gaps in the castes when molding the fixtures. As high as 90% of all plumbing fixtures are made of brass or bronze. Because of this, all water systems have the potential to leach lead into the drinking water. This is a good reason to recommend that the client get a laboratory analysis of the water in the home.