Bath: plumbing design and Bill of Materials

[msimerson]

Design

• water is very expensive
• plumb with the ability to integrate future gray water system
• PEX A, because they have in house experience
  • support every 32" (min)
• All hot and cold water pipes installed outside the conditioned space shall be insulated to a minimum R-3.
• IPC 407.2.1 The maximum flow rate for public lavatory faucets shall not exceed 0.5 gpm at 60 psi.
• IPC 407.3 Hot water delivered from public-use lavatories shall be limited to a maximum temperature of 120°F
• IPC 411.2 The effective flush volume of all water closets shall not exceed 1.28 gallons
• IPC 412.1.1 Where nonwater urinals are installed, not less than one water supplied fixture rated at not less than 1 water supply fixture unit (WSFU) shall be installed upstream on the same drain line to facilitate drain line flow and rinsing.
• IPC 419.5 Tempered water (85-110°) for public hand-washing facilities. Tempered water shall be delivered from lavatories and group wash fixtures located in public toilet facilities patrons and visitors. Tempered water shall be delivered through an approved water-temperature limiting device that conforms to ASSE 1070/ASME A112.1070/CSA B125.70 or CSA B125.3.
• Floor drains shall be installed in ... toilet rooms containing two (2) or more water closets... The floor shall slope toward the floor drains.

Permitting

• King County Public Health: permit: $389
• KCEH says, based on scope of work, plan review is not needed (yay, that takes 18-24 weeks)

Bill of Materials

is here.

[msimerson]

2022-05-11 Stevens Plumbing Permit.pdf

[msimerson]

Plumbing Notes

• King County: Horizontal wet venting (circuit)
• ICC Safe: Circuit Venting
• 2021 IPC, Methods of venting plumbing fixtures and traps (Circuit venting, combi waste & vent, single stack
• Fine Homebuilding, Vent Options for Plumbing Drains (Back / continuous / dry) venting, stack venting, loop vents.