Photograph of  this antiquated laundry sink with several unsanitary plumbing violations in view. Plumbing System Installation & Repair

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Building plumbing system installation, inspection, troubleshooting & repair:

Guide to articles describing plumbing systems, piping, components: installation, inspection, troubleshooting & repair, organized by topic.

These plumbing repair articles answer nearly all questions about diagnosing and repairing building plumbing systems, including water supply and drain piping, vent piping, gas and oil piping in buildings, plumbing fixtures, water heaters, water pumps, water pressure, water softeners, water testing, water treatment equipment, water wells, and septic systems.

We also explain oil tanks, water tanks as well as other building plumbing system inspection or defect topics.

Also try the page top or bottom SEARCH BOX as a quick way to find information you need.

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Plumbing System Diagnosis and Repair Guides

Photograph of  a modern steel well casing and cap extending properly above grade level and properly capped. You can see from
the gray plastic conduit that electrical wires enter the well, informing you that this well is served by an in-well submersible well pump. This InspectAPedia page provides links to both article indexes by major plumbing topic and links to in-depth articles on inspecting, testing, and repairing problems with above ground and buried oil tanks, septic system design, inspection, testing, water supply and drain waste vent piping, wells, water supply pumps, water tanks, water testing and water treatment. New York State License # 16000005303 (inception to 2008)

Below on this page we describe the contents of key plumbing system articles and indexes organized by major plumbing system topics.

To find what you need quickly, if you don't want to scroll through this index you are welcome to use the page top or bottom SEARCH BOX to search InspectApedia for specific articles and information.

For a complete index to articles about plumbing systems, controls, equipment, fixtures, pipes, etc. see ARTICLE INDEX to PLUMBING SYSTEMS

Drinking Water Tests, Water Contamination Limits, Drinking Water Testing Procedures

Fixtures, Plumbing: Sinks, Tubs, Showers, Toilets, Toilet Alternatives


Gas Piping in buildings

Hot Water Systems: Water Heaters

Oil & Gas Fuel Supply Piping and Tanks

Photograph of  this leaking indoor heating oil storage tank.

Plumbing Information Master Index

Plumbing Codes, Citations, Fulltext Codes, & Plumbing Code References

Plumbing System Design Guide USDOC at InspectApedia.comWatch out: while for the US the 2015 IPC is the most-recent version of the International Plumbing Code, while the 2018 IPC is under development.

To understand which generation of the model building code or plumbing code applies to your specific project you will need to check with your local building official. For example many jurisdictions are on the 2012 IPC or still older versions.


The Septic Information Website - FREE!Septic Systems & Septic Tanks: Onsite Waste Disposal - Septic Systems Inspection & Testing, Problem Diagnosis & Repair Procedures



Water Supply Piping, & Drain Piping, other Building Pipes and Plumbing piping failures, leaks, and litigation

Photograph of  this interesting double s-trap.

Water Supply Piping, & Drain Piping, Water Supply Equipment, other Building Pipes and Plumbing

The following basic water supply information is adapted with permission from Carson Dunlop AssociatesHome Reference Book.

For complete water pressure problem diagnosis see WATER PRESSURE LOSS DIAGNOSIS & REPAIR and see our water pressure diagnostic table at WATER PRESSURE PROBLEM DIAGNOSIS TABLE.

Also see WATER HEATER PIPING - how are individual or mulitiple water heaters hooked-up: how are water heater pipes and heaters cascaded, ganged, in series, in parallell

Public Water Supply Piping Properties, Pressure & Flow Problems

If your water supply is from a municipal supply and there are pressure or flow problems, see MUNICIPAL WATER PRESSURE DIAGNOSIS. Excerpts are below.

Typically, the water mains in residential areas are four inches to 12 inches in diameter, and run several feet below the street level.

Smaller pipes, usually 1/2 inch or 3/4 inch diameter, run from city mains into buildings. The water is normally supplied at a pressure of 40 to 70 psi (pounds per square inch).

Typical Water Service Piping from Public Water Main to Building Interior

The 1/2 inch or 3/4 inch diameter service piping carries the water from the street mains to the house. Some early service pipes were 3/8 inch diameter. Most or all of this cannot be seen.

Lead Water Service Piping

Lead piping was used between the street main and the house up until the 1950s.

A good deal of lead supply line is still in use, and the health authorities indicate that as long as it is used regularly, there is no difficulty with it. If the water has not been run for some time, many recommend that the water be flowed for several minutes before using it. The life expectancy of lead piping is indefinite. See

Other water piping materials: Copper, Galvanized Steel, Plastic

Copper piping has been used extensively since the early 1950s for supply lines from the city main to the house. From 1950 to 1970, 1/2-inch diameter piping was used commonly. After 1970, 3/4-inch diameter copper service piping has been common.

The life expectancy of copper piping is dependent on water conditions. In many areas, its life expectancy is indefinite. In harsh water or soil conditions, it may fail within 20 years.

Galvanized steel is not commonly used as a service pipe, although galvanized steel fittings may be found at the point of entry into the house. Where galvanized service piping is used, it is typically at least 1 1/4-inch diameter. The word galvanized means zinc-coated. The coating helps prevent the steel from rusting.

Plastic water service piping may be polybutylene (PB), polyethylene (PE), cross-linked polyethylene (PEX), polyvinyl chloride (PVC) or chlorinated polyvinyl chloride (CPVC).

Most plastic piping is buried at least 18 inches deep. Exposed piping may be subject to mechanical damage and deterioration from sunlight.

Common Water Service Piping Defects and Problems

Leaks in Water Service Piping

Since the supply line from the street cannot be seen, no comment is offered during a home inspection. If there is a leak, it may go undetected for some time. In some cases, water can be heard running outside the basement wall. Water accumulating in the basement or a wet spot on the lawn is often the first indication.

Leaks may be caused by building settlement, excavation, poor connections, faulty valves or a flaw in the pipe itself.

The underground water service line from the property line to the house is owned by the homeowner. Beyond the property line, the pipe is the responsibility of the city. A leak in the pipe requires excavation, and it is often difficult to know whether the leak is on the city’s or the homeowner’s side.

The city is usually contacted and they excavate their section of the pipe, correcting the problem if they discover it. If no problem is found, the homeowner is left to correct the problem on his or her own. In some cases, the homeowner must pay for the city’s work if the city pipe is not at fault. Some municipalities use sophisticated leak detection equipment.

Low Water Pressure Due to Clogged Service Piping

Poor water pressure in the house may be the result of a partially closed or obstructed valve in the street. It may also be because of blockage, such as a stone or other foreign body in the pipe. New piping may be crimped during installation or become pinched under a rock during back-filling operations. This can also cause low water pressure.

City water mains may be undersized or deteriorated in older neighborhoods. Some cities have poor pumping and/or distribution systems. In these cases, low water pressure problems are usually experienced at every home in the neighborhood. The solution is to petition the city to improve its system.

Water Service Piping Too-Small in Diameter

In most new housing, the supply pipe from the street to the house is 3/4-inch diameter. In older houses, the piping was as small as 3/8-inch

. Modern life styles and additional plumbing fixtures usually require a larger line, capable of providing more pressure and volume. Replacing this pipe is an expensive and disruptive job. It is often deferred as long as possible.

Shared Public Supply Service Piping May Cause Poor Pressure or Flow

In some older semi-detached (attached) and row houses, a single supply line would run under a front lawn, and then split to feed two houses. This often yields unsatisfactory water pressure for both houses and is often replaced with two larger, separate lines.

Pressure Regulator Needed on Public Water Supply Piping

Where municipal water pressure is above 80 psi, [perhaps even above 70 psi] a regulator Needed should be provided to reduce the in-house pressure to prevent leaks at fixtures, stress on appliance hoses and possible broken pipe joints.


Freeze-Up Problems with Municipal Water Supply Piping

It is unusual, although not impossible, for the service pipe to be too close to the surface, and to freeze during very cold weather. Many service pipes extend above grade just before they enter the house.


Lead Municipal Water Mains or Water Service Piping

Up until World War II, most of the service pipes in built-up areas were lead.

While these generally provide good service, they are small in diameter and may have to be replaced. Also, lead is relatively soft, and if building settlement occurs, there is a chance of leakage or crimping the pipe. Leaks can also occur at connections as a result of long-term deterioration.

Lead Water Service Piping Connected to Steel Pipe Nipple: Leak Risk

Many of the old lead service lines were connected to a galvanized nipple – a short piece of steel pipe that was often in contact with the soil.

This pipe rusts on the outside and inside, and may be close to the end of its life. It is often wise to replace this as a precautionary measure. Galvanized steel service pipes typically last roughly 40 years.

See details at LEAD PIPES in BUILDINGS.

- Adapted from Carson Dunlop AssociatesHome Reference Book.

Water Supply Sources: Wells, Water Pumps, Water Tanks: Inspection, Diagnosis, Installation, Repair, Maintenance

Water Tanks, Water Pumps, Well Pumps

Wells, Cisterns, Springs: water supply problem diagnosis and repair


Continue reading at LEAK TYPES, WATER SUPPLY or DRAIN PIPES or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see PLUMBING SYSTEM INSPECT DIAGNOSE REPAIR FAQs - questions & answers posted originally at this page.

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PLUMBING SYSTEM INSPECT DIAGNOSE REPAIR at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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