A: For waste water to properly drain, there must be air behind the water which requires a plumbing vent above the roof. In some instances, an automatic air vent or air admittance valve can be used ...

A: For waste water to properly drain, there must be air behind the water, which requires a plumbing vent above the roof. In some instances, an automatic air vent or air admittance valve can be ...

If you poke a drinking straw into your soft drink and place a finger over the opening, you can lift the straw out and the liquid in the straw will stay. Remove your finger and the liquid runs out.

Plumbing vent pipes have to be sized correctly, they need to have a slope to them to drain any condensate back to the drain pipes, and they must be installed with great care. (iStock) Perspective ...

I really enjoyed the challenge of the three-dimensional problem-solving you have to do to run all the drain and vent pipes in a typical home. I wondered how it all worked and was lucky enough to ...