Water Supply Piping, & Drain Piping, Water Supply Equipment, other Building Pipes and Plumbing
InspectAPedia® -
Wells & water tanks, water supply piping, drain waste & vent piping, water supply: how to inspect, diagnose, test, repair water supply & drain piping
Tank Types Encyclopedia an encyclopedia of tanks in buildings, water tanks, oil tanks, gas tanks, expansion tanks, cisterns, antique, modern
Life expectancy of lead water piping
Life expectancy of galvanized steel water piping
Life expectancy of copper and plastic water supply and drain piping
Our site offers impartial, unbiased advice without conflicts of interest.
We will block advertisements which we discover or readers inform us are associated with bad business practices,
false-advertising, or junk science. Our contact info is at
InspectAPedia.com/Contact.htm.
This page lists our in-depth articles on inspecting, testing, and repairing problems with building plumbing: water supply and drain waste vent piping, plumbing traps, piping materials, clogged or noisy pipes, and types of pipe hazards or product defects. New York State License # 16000005303 (inception to 2008). Other types of building piping systems are discussed at GAS PIPING, VALVES, CONTROLS and at OIL TANK PIPING DEFECTS.
The articles at this website will answer most questions about water supply & drain piping, wells, & water tanks
as well as many other building plumbing system inspection or defect topics.
Sketch of piping details that affect the water supply in a building is provided courtesy of Carson Dunlop.
Reproduction of this web page electronically at other websites is prohibited.
Cast iron drain piping has been used in buildings for more than 100 years. This heavy material is available in diameters from 2" and up, with typical main building drains of 4" to 6" in diameter. A hub system connects pipe sections, originally using melted lead.
The cast iron pipe hub and stub were wiped with oil to remove water, avoiding a dangerous steam flash when lead was poured into the fitting. Most modern cast iron connections are made using rubber or plastic fittings that no longer require heating and melting lead.
The illustrations (left) show accessing a cast iron drain cleanout and two methods of emergency, temporary repair of leaks in drain piping.
The following summary notes about copper and other types of building piping are from Carson Dunlop Associates' Home Reference Book, used with permission:
Copper piping has been used extensively since the early 1950s for supply lines from the city main to the house as well as for in-building water supply and drain piping.
Copper water supply piping is typically 1/2 or 3/4 inch diameter. Copper piping is typically 1/2 or 3/4 inch diameter. Copper piping has soldered connections and the walls of the pipe are thinner than galvanized steel. Copper piping has soldered connections and the walls of the pipe are thinner than galvanized steel.
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 corrosive water or corrosive soil conditions, it may fail within 20 years or even less. Occasionally manufacturing defects also result in early failure of copper building piping.
Carson Dunlop Associates' sketch (left) illustrates three types of copper piping used in buildings for water supply or drains.
Type M copper piping is used for general plumbing, above ground. Type M copper tubing walls are the thinnest used in construction, at 0.026" in wall thickness and thus more vulnerable to leaks if water being handled is aggressive or corrosive.
Type L copper piping is also used for general plumbing as well as for heating system piping. Type L copper tubing walls are thicker, at 0.040".
Type K copper piping is used for plumbing, heating, gas lines, and underground, and has a wall thickness of 0.049".
Flexible copper tubing used as water piping: Flexible copper tubing can be bent around corners using special tools. This is not common since it is more expensive and can be awkward to work with in close quarters. Flexible copper tubing is also used for oil piping (OIL TANK PIPING DEFECTS) and natural gas piping (GAS PIPING, VALVES, CONTROLS).
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.
Galvanized steel piping was common until roughly 1950. This piping typically lasts 40 to
60 years. Some lower-quality pipes do not last as long and there are some oversized pipes still in use after 60 years. Where it is found today in single-family homes, it is usually near the end of its life.
Life expectancy of galvanized steel piping: Galvanized steel supply pipes
are typically 1/2-inch diameter. The connections are threaded. When the pipe corrodes, the rust accumulation inside the pipe chokes down the diameter of the pipe, resulting in poor water pressure.
Rust also attacks the pipe walls, making the walls thinner. Eventually, the pipe will rust through, usually at the joints first, resulting in leakage.
Our photographs (below) show galvanized drain piping in use in buildings. At below left, the cleanout in a galvanized drain line has been lost, plugged with who-knows-what, and is an odor and leak source. At below-right, the rope trying to secure the galvanized drain line to the cast iron sewer piping confirm a history of leak troubles and improper plumbing connections.
Lead Water Supply & Drain Piping in Buildings
See our detailed articles about lead plumbing pipes in buildings at
LEAD PIPES in BUILDINGS - identification of lead drain or water supply piping, durability, leaks, health questions
Portions of the following summary are from Carson Dunlop Associates' Home Reference Book, used with permission:
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.
Our photographs show a lead water entry main or service pipe (below-left) and lead plumbing drain piping (below-right).
The life expectancy
of lead water supply piping is indefinite in some soils and in more corrosive soils we have plumbers' opinions that the service life of buried lead water supply piping is 40 to 50 years. See LEAD WATER PIPES and LEAD WATER PIPING HAZARDS & REMEDIES for details.
Plastic Building Water Piping & Tubing
See PLASTIC PIPING for details about plastic drain and supply piping in buildings, including its history, failures, warranty claims, class actions, and present usage in construction.
Plastic water service piping may be polybutylene (PB), polyethylene (PE), cross-linked
and Tubing Tubing Tubing Tubing Tubing Tubing Tubing 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. - Home Reference Book, used with permission.
Other water supply and drain piping and water pressure articles:
Pressure/Temperature Relief Valves, proper inspection methods, issues and hazards (article due in 2007)
Clearances Required for Wells Distance Between Well & Septic System and other water pollution sources, Online Table of Well Distances
FREEZE-PROOF PIPES: how to freeze-proof plumbing in a building, how to avoid freezing pipes, how to thaw frozen pipes: how to winterize a building against freezing and frost damage.
HOT WATER HEATERS - a detailed guide to all types of hot water sources, problems, inspection, repair
Plastic Water Supply & Drain Piping Failures, Leaks, Repairs, Lawsuits: Water Supply Piping Defects and Plastic or polybutylene water supply piping failures, leaks, and litigation.
PLASTIC PIPING - Leaks, Repairs, Lawsuits: Water Supply Piping Defects and Plastic or polybutylene water supply piping failures, leaks, and litigation.
Our main article on plastic supply and drain piping leaks, failures, litigation, repairs, at PLASTIC PIPING. Excerpts are just below.
PB (polybutylene with mechanical fittings) Piping leaks: especially in mobile homes and in the U.S. South, for example trailers and double-wides throughout Florida that were piped with this material - per M Cramer. See "Polybutylene Piping: Time Bomb?" Daniel Friedman, Journal of Light Construction, August 1996 [Technical Q&A].
If plastic water piping is installed, such as polybutylene water supply piping, it should be at least 18" from the water heater.
New mobile home and trailer units: 3/4" supply piping, min 6" off ground; shutoff valve required;
Tank Types Encyclopedia an encyclopedia of tanks in buildings, water tanks, fuel tanks, gas tanks, heating system expansion tanks, oil tanks, water cisterns, water pressure tanks, pressure booster tanks, antique, modern
Water Tanks - how to diagnose problems with water tanks, such as the need for air, how to add air, stop water pump short cycling to avoid damage - water storage water pressure tank safety.
Water Testing for contaminants in drinking water - what test are available, what tests to ask for, what they cost, how people cheat on water tests
Wells, Cisterns,& Springs types of sources of drinking water, what they look like, what goes wrong, what to do about it
Basement Wells as a water source, what to watch out for, how to inspect, test, make safe
WINTERIZE A BUILDING: how to freeze-proof plumbing in a building, how to avoid freezing pipes, how to thaw frozen pipes: how to winterize a building against freezing and frost damage.
Plumbing Links our big list of links to plastic piping and other plumbing defects
Critique, contributions wanted: Contact Us to suggest corrections or additions to articles at this website, and if you wish, to receive online listing and credit as a contributor. Particular thanks are due to the many experts and also consumers who read and critique technical articles at InspectAPedia.com.
Additional technical contributors & reference sources for this article are listed below.
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.
Mark Cramer Inspection Services Mark Cramer, Tampa Florida, Mr. Cramer is a past president of ASHI, the American Society of Home Inspectors and is a Florida home inspector and home inspection educator. Contact Mark Cramer at: 727-595-4211 mark@BestTampaInspector.com 11/06
Roger Hankey is principal of Hankey and Brown home inspectors, Eden Prairie, MN. Mr. Hankey is a past chairman of the ASHI Technical Committee and the ASHI Standards Committee. Mr. Hankey serves as co-chairman of ASHI legislative committee, and has served in other ASHI professional and leadership roles. Contact Roger Hankey at: 952 829-0044 - hankeybrown@comcast.net
Arlene Puentes, an ASHI member and a licensed home inspector in Kingston, NY, and has served on ASHI national committees as well as HVASHI Chapter President. Ms. Puentes can be contacted at ap@octoberhome.com
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
er
Plumbing Diagnosis & Repair: Water supply, drainage, septic systems, water testing, water contamination, defective plumbing materials & products.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop, and from the InspectAPedia bookstore. The 2010 edition of the Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Cheating on water tests: Testing Water for Real Estate Transactions - make sure your water test is valid
InspectAPedia ® Home & Site Map
Cast iron drain piping has been used in buildings for more than 100 years. This heavy material is available in diameters from 2" and up, with typical main building drains of 4" to 6" in diameter. A hub system connects pipe sections, originally using melted lead. 
