Waste Vent In Attic

I have a customer that we are doing some work in the attic for and i noticed yesterday that the plumbing is vented up into the attic phew and not thru the roof.

Waste vent in attic.

Notice how the main vent and waste pipe remain separated behind the sink only connecting via the attached went pipe. The first would be a bathroom or kitchen in that part of the house and the other would be a. I see situations around like this sometimes. These empty into larger waste pipes that connect to the sewers.

As the water runs down proper venting is required to avoid a vacuum from being created. Water running through these pipes tends to create a suction behind it and that suction can be. Extra info on the air admittance valve. Only two plumbing set ups could require sewer pipes in the attic.

There are 3 vents in one area and 2 in another. The drain waste vent system everyone knows what drain and waste pipes are but not everyone understands the function of the vents. The vent pipes remove or exhaust sewer gases and allow air to enter the system so that the wastewater flows freely. The drainpipes are made of cast iron galvanized pipe copper or plastic.

Vent pipes look like sewer pipes. The waste pipes remove water and material from the toilet. Drain pipes are those connected to fixture p traps. In modern plumbing a drain waste vent or dwv is part of a system that allows air to enter a plumbing system to maintain proper air pressure to enable the removal of sewage and greywater from a dwelling.