Guide to Types of Leaks in Water Supply & Drain Piping InspectAPedia® -
A simple guide to the types of leaks that occur in water pipes, drain pipes, & plumbing fixtures
Water supply pipe and well pipe leak types & diagnosis
Catalog of types of plumbing leaks helps find leaks in buildings
When where, why, and how to check for & fix water supply and drain leaks
How to de-winterize a building and restore the plumbing & heating systems to service
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This article describes the different types of plumbing leaks that can occur in building supply piping or drain piping. Knowing just what kind of leak is occurring in a building helps pinpoint the problem and also helps specify the necessary plumbing repair. The articles at this website will answer most questions about freeze protection for piping and other building plumbing and heating system components: how to winterize a building to avoid frozen pipes, and how to thaw frozen water supply & drain piping, wells, & water tanks.
A Quick Tutorial on Types of Water Supply & Drain Pipe Leaks Helps Find Leaks in buildings
Understanding the types of water leaks that occur in building piping can help you find or watch out for leaks that are not so obvious when water is first turned on in a building. Keep in mind that these are by no means all of the building leaks that can occur. Others include leaky shower pans, leaky air conditioning condensate drains, bad sump pump drains, leaky water tanks, leaky water heaters, leaks at tankless coils, and leaks from outside the building from roof runoff or surface runoff. Here we focus attention on leaks that occur in building piping:
Types of Leaks in Water Supply Piping
Gusher water supply pipe water leaks: if a water supply pipe has burst, split, been cut open, or has separated at a solder joint, as soon as water is turned on to that area of the building the pipe will probably leak a lot of water very quickly: you will notice gusher leaks almost immediately by sound or by the visual evidence of water flooding or wetting some area of the building.
Drip and pinhole water supply pipe leaks: a small leak may be present at a water supply pipe such as from a loose threaded fitting, worn valve stem packing, or even a pinhole due to corrosion or due to a nail or screw having been driven into a supply pipe. These leaks can take a longer time to discover because the rate of leak is so slow. (Don't pull out that nail or screw when you find it until you've first shut off the water supply or a bigger leak will ensue.) But these leaks normally are indeed discovered in days or weeks after they occur. Also see WELL PIPING LEAK DIAGNOSIS below.
Plumbing fixture faucet leaks: sometimes a sink, tub, or shower faucet develops a leak, usually around the valve stem packing, that will leak only when the valve is in the open position - that is, when water is running at that faucet. These leaks fall in two sub-classes: visible and hidden.
A visible water faucet leak shows up where you can see it, such as dripping into the sink, tub, or shower around the faucet control when the control is opened, but stopping when the faucet is shut.
A hidden water faucet leak is much more sneaky. Particularly at tub and shower controls mounted on a vertical wall, some faucets may leak inside of the wall cavity when the faucet is open and water is running. Because these leaks are usually just a slow drip, the leak may be present for months or even longer before it is finally noticed. Typically these surreptitious faucet leaks show up as a stain in a ceiling below the fixture or as mold or moldy odors in a building. Opening a wall or ceiling cavity may be necessary to find and repair such leaks.
Types of Leaks in Building Drain Piping
Plumbing drain leaks: plumbing drain leaks are a bit like our hidden water faucet leak: they only show up if the particular leaky drain is carrying wastewater. For example, a leaky shower trap in an upstairs shower may go unnoticed for a long time if it's the guest-bath shower that is rarely used.
Except where the drain pipes are visible, such as in a basement or crawl space, plumbing drain leaks may be slow to appear and show up as a stain in a ceiling or wall below the offending drain, or as mold or mold odors in a building.
Of course if a plumbing drain has literally burst or fallen open the leak will be enormous and will show up quickly as was the case with our gusher water pipe leaks described above.
At WATER PRESSURE PROBLEM DIAGNOSIS TABLE we note that a possible explanation for loss of building water pressure, or loss of well pump prime can be air leaking into a well piping line, as well as water leaking out of the well pipe.
Water will leak out of a well pipe at a bad connection, perforation, or cracked pipe when the well pump is running, particularly if the water system uses a submersible pump that is located in the well itself. If you have this problem you may find a wet spot in the ground near the well piping, provided that the pipe is close enough to the surface. You will also notice that the well pump is running more often than normal, and that your "apparent" water usage may have increased. Some people even report finding a "water fountain" or geyser in the lawn at a burst water supply pipe from both private wells and from a municipal water main.
Air may leak into a well water pipe at a bad connection, peforation, or other damage when the well pump stops running, particularly if the leak problem is combined with a defective check valve or foot valve in the piping system. The result may be air discharged from plumbing fixtures (see AIR DISCHARGE at FAUCETS, FIXTURES), improper air charge in the water pressure tank, or loss of pump prime. Short cycling of the water pump or loss of pump prime may result as well.
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"Freezeproof Your House," Mike McClintock, Rodale's New Shelter, p. 30, October 1985 (approximate date)
"How to Winterize Your Pipes," Mike McClintock, Homeowners How-To Magazine, p. 59-62, Nov-Dec 1979.
Thanks to reade Dan Babb for discussing well piping leaks, July 2010
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