Chapter 20
Plumbing Plans
Introduction
• Classifications of piping:
– Industrial or residential (i.e., plumbing)
• Types of pipes:
– Copper
– Plastic
– Metal
– Steel
– Cast iron
Introduction (cont’d.)
• Residential plans
– Generally don’t require complete plumbing
plan
• Need should be verified with local building code
– In most cases, requirements can be provided
on floor plan
• Symbols for fixtures
• Notes for specific applications or conditions
Plumbing Terms and Definitions
• Key terminology:
– Cleanout
– Drain
– Fitting
– Hose bibb
– Main
– Plumbing fixture,
system, and wall
– Potable water
– Riser
– Rough-in
– Run
– Sanitary sewer
– Sewer
– Soil pipe and stack
Terms and Definitions (cont’d.)
• Key terminology (cont’d.):
– Stack
– Storm sewer
– Trap
– Valve
– Vanity
– Vent pipe and stack
– Waste pipe and stack
– Water closet
– Water distributing
pipe
– Water heater,
main, and meter
– Water service
Size of Plumbing Piping
• Water supply plumbing is based on:
– Amount of water needed
– Supply pressure
– Pipe length
– Number of stories to be supplied
– Flow pressure needed at farthest point
Size of Plumbing Piping (cont’d.)
• Size of drainage piping is based on:
– Standards established for fixture type
– Average amount of waste discharged through
the fixture in a given amount of time
• Size of vent pipes is based on:
– Number of drainage fixture units that drain into
waste portion of vent stack
Universal Plumbing Installations
• Design considerations:
– Sinks
– Water closet
– Bathtubs
– Showers
Plumbing Schedules
• Similar to door,
window, and lighting
fixture schedules
– Mortgage lenders may
require a complete
description of
materials
Plumbing Drawings
• Usually not on the same sheet as complete
floor plan
– Only plumbing items on floor plans are fixtures
– Generally drawn separately
– Floor plan is used as a base drawing
– May be prepared by a drafter or in conjunction
with a plumbing contractor
Water Systems
• Water supply to a structure begins at a:
– Water meter for public systems
– Water storage tank for private well systems
• Water supply to home or business:
– Known as the main line
– Generally 1" plastic pipe
Water Systems (cont’d.)
• Water heaters
– Placed on a platform with an overflow tray
– Recommended sizes vary
• Hose bibbs
– Faucets used to attach a hose
– Outside hose bibbs require a separate valve
• Allows owner to turn off water to hose bibb during
freezing weather
Drainage and Vent Systems
• Drainage system
– Provides for distribution of solid and liquid
waste to sewer line
• Vent system
– Allows continuous airflow through the system
• Gases and odors can dissipate
• Bacteria do not have an opportunity to develop
Isometric Plumbing Drawings
• Provide threedimensional
representation of a
plumbing layout
(i.e., plumbing riser
diagram)
Automatic Fire Sprinkler Systems
• 2009 International Residential Code (IRC)
– Section P2904 of the International Plumbing
Code (IPC)
• Requires automatic fire sprinkler systems for all new
townhouse construction
• Not required on additions or alterations made to
existing townhomes
Sewage Disposal
• Sanitary sewer system
– Underground pipes collect and transfer
wastewater to treatment plants or private
sewage treatment
• Includes domestic, business, and industry
• Not designed to handle storm water
– Systems:
• Public sewers
• Private sewage disposal (e.g., septic tank)
Fire Sprinkler Systems
• Commonly used in commercial buildings
– Becoming a consideration in residential design
• Sometimes required
• Determined by local governing agency, by square
footage or location
– Water plug releases water when heat reaches
a certain temperature
• Several advantages
Metrics in Plumbing
• Pipe is made of a wide variety of materials
– Identified by trade names
– Nominal sizes related loosely to actual
dimensions
• Metric values established by International
Organization for Standardization
– Relate nominal pipe sizes in inches to metric
equivalents (i.e., diameter nominal)
Adding Plumbing Information to
the Floor Plan
• Residential floor plan drawings plumbing
symbols and notes
– May be placed with all other floor plan content
• Aid in reading and understanding
• Notes are generally minimal
– Can also be placed on a separate drawing
Commercial Plumbing Drawings
• In most cases, are an individual component
of the complete set of plans
– Architect or mechanical engineer prepares
plumbing drawings over base floor plan
• Keeps drawing clear of unwanted information
• Makes it easier for the plumbing contractor to read
the print
Plumbing Plan Drawing Checklist
• Refer to the text for a plumbing plan
drawing checklist
– Check off items as you work on the plumbing
plan
• Ensures all of necessary items are included