“I don’t like inline shut off valves,” says our plumber friend James Freeman, “because if the supply line leaks before the valve you have to shut down the water to the whole house until it gets repaired.” We agree with James and, because a supply line has a shorter lifespan rating than pipe, odds are it will leak first.

    The plumbing code requires a shut off valve within sight for each supply pipe to each fixture. Because the code does not spell out that it has to be on the pipe before the supply line, a municipal inspector might let an inline valve slide. But we doubt it.

   The in-line shut off valve shown above was in the bathroom of a 1950s house we inspected yesterday. Original galvanized steel water supply pipe had been mostly replaced, except at the risers inside the walls to the bathroom. As it turned out, there already was corrosion and leakage beginning at the pipe-to-supply-line connection at the wall at one location, as shown in the photo below; and, as James predicted, they will have to turn off the water to whole house to fix it.

Also, see our blog post Which plumbing fixtures require water shut off valves in a home?

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Here’s links to a collection of our blog posts about SHUT-OFF VALVES: 

• How do I find the main water shut off valve for my house?

• How do I shut off the main water service in a mobile/manufactured home?

• Where do I find the main water shut-off valve for my condominium?

• Does a home inspector check and test shut-off valves?

• Which plumbing fixtures require water shut off valves in a home? 

• Is a hot water faucet required at a washing machine?

• Does a refrigerator water supply line require a shutoff valve behind it?

• Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater?

• Is a shut-off valve required at the cold water inlet to a mobile home water heater?

• What is the average life expectancy of plumbing fixture water shut-off valves? 

• Is it alright to have a shut-off valve on both the hot and cold water pipes at a water heater? 

• Is a sink or toilet shut-off valve behind an access panel approved by code?

Visit our PLUMBING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.