Plumbing Venting
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Good reference:
Vent to drain distances included. Island venting. Air admittance valves. Engineered vent with sump pump and air admittance - like under sink macerator pump.
https://wabo.memberclicks.net/assets/pdfs/Plumbing_Venting_Brochure_2018.pdf
Design
- Drainage figture unit - DFU - 7.5gpm or cubic foot of water through 1.25" pipe.
- Vents are 10' away from windows or air intakes, or 3 feet above. [1]
- Good openslides on basics - [2]
- Vent stack vs stack vent - a stack vent is required in addition to vent stack for 5 stories or more [3]
- Island venting - for example an island sink as in this video - [4] - you can use an air admittance valve, or you can use an island fixture vent loop.
- Vent exends 6" above roof, except if roof is used for purposes other than weather protection - in which case it's 7'. [5]
- Vent is half diameter of drain served. [6]
- Washing machine needs a trap - [7]
- Vent stacks can run up the side of a house - [8]
- Total vent cross sectional area must equal total drain cross sectional area. See point 6 at [9]. Note that air admittance valves add to the total cross sectional vent area.
- 1/8" slope per foot is acceptable for 3" pipe - [10]