Have You Got The ‘New House plumbing Blues’?

Have You Got The ‘New House plumbing Blues’?

or What’s wrong in this picture.? A Plumbing Puzzler.

new and clean but not right

Everything is clean and new and dry, no leaks. It’s a new house, less than 2 years old, being sold by the builder owner.

He (or his plumber) would get 3 out of 4 on this issue because of the 4 sinks in the home only this one is like this. Very likely, one person did the rough-in plumbing (blue and red lines) and later, somebody else connected the sinks at a finishing stage.

The plumbing IS all clean and new. There are no leaks and all the parts are there, so what’s wrong.

Look at the copper parts at the ends of the ‘t’ offshoots. As they are installed they are filled with water and that defeats their purpose and function.

correct sink connections

This shows another sink in the same house done correctly.

Here you see the intended installation position. Air is trapped in those vertical chambers.

The air is compressible (water is not) and provides a cushion to counteract shocks or pressure changes in the water supply lines resulting from valve switching or flow changes from other fixtures and equipment in the system.

Noise can be caused by these pressure changes in systems that don’t have such a dampening device. This is called ‘water hammer’ and indeed it is a hammering repetitive noise.

The noise can be quite loud and intrusive. In older more brittle plumbing systems it can be violent enough to cause leaks or breakage. Sometimes the noise can be of a high enough frequency to sound like whistling or singing, but it is commonly low bass tones that transmit well through the structure.

The “noise arrestors” won’t always be these pre-made bottle shaped parts. Plumbers commonly create them on the spot with standard plumbing supplies. All that is required is a capped vertical pipe section open only in the downward direction.

Non-professionals often see these spurs or offsets and think it is unfinished work or provision for future connections.

They can be located anywhere in the system and are often found near sinks or showers and near hot water tanks and radiators of hot water heating systems.

system illustration

This illustration shows 8 of these “air chambers” in this example of a residential water supply system.


Comparatively this is a minor mistake, easily corrected and not a major cost. But it’s significance is in the future performance of the plumbing in this new home.

This is also one example of why it is just as important to have a new home fully inspected. Just because it’s new, built with all new components, doesn’t mean it’s always done right.


Original blog post on ActiveRain: Link to Blog Post