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35 house . Hose bibbs should be frost-proof , with integral backflow prevention capabilities or as required by the local jurisdiction . The UPC guides the end-user to bury the supply piping not less than 12 inches below the local frost line for protection . The NSPC and UPC require specific minimum vent terminal sizing , above , below , and through the roof to prevent these vent pipes from freezing . For example , the NSPC contains : “ Where the Authority Having Jurisdiction requires protection against frost closure , vent terminals less than 3 ” pipe size shall be increased at least one pipe size to not less than 3 ” size . Where an increase is necessary , the increase in size shall be made inside the building at least one foot below a roof or ceiling that is thermally insulated , and in an area not subject to freezing temperatures .”
Specific to Tiny Houses So far , we have discussed general plumbing provisions that pertain to all plumbing systems , regardless of size . The 2021 NSPC contains a new appendix ( Appendix L ) for tiny houses . The appendix separates the provisions between single tiny houses ( Part I ) and tiny house communities ( Part II ) as there are distinct requirements for “ tiny house communities ” that are not required when a lot contains a single tiny house . Section L . 2.1 of the NSPC defines a tiny house community as follows :
• “ Tiny House , Community : A structure ( s ), where erected , is 400 square feet ( 37m ²) or less , and of not less than two structures in the same lot .”
• The new appendix contains specific provisions for tiny houses such as requiring a kitchen with no fewer than one sink and a restroom with no fewer than one water closet , one lavatory , and one water-tight bath , shower or combination bath / shower . Further , the new Appendix refers the reader to the appropriate code sections for ease of use of the code for compliance .
• The appendix also contains dimensional provisions for bathrooms , such as a minimum ceiling height no shorter than 6 feet 8 inches ( 2 032mm ) from the floor when measured at the center , front area of the fixtures . Ceiling heights above fixtures should not interfere with the fixture ’ s intended purpose . Showers or combination bath / shower require a ceiling height no shorter than 6 feet 8 inches ( 2 032mm ) where measured from the shower drain . Because of spacing limitations , the provisions in the NSPC appendix give designers the minimum spacing requirements in tiny house restrooms with the intent that the space is usable , and the fixtures are placed with enough space to utilise safely .
There are many choices and possibilities when designing and building a tiny house . The UPC and NSPC are valuable documents giving the person appropriate guidelines for plumbing systems . Since the number one focus is “ health and safety ” of the public , these respected codes provide a wealth of information that will assist in completing a wellbuilt tiny house plumbing system for years to come . PA
Macerating or sewage pump toilets may be an option where pumps are necessary to push waste uphill to reach a drainage system .
January 2021 Volume 26 I Number 11 www . plumbingafrica . co . za