While running departments and teaching classes the following
questions have been asked and many times theanswer seems confusing.
The following is an interpretation and/or explanation of the 2009 I
codes and 2008NEC and as always it is up to the building official
to interpret the intent of the code.
John England has been teaching inspectors and building officials
for over 16 years. For further information on this code question
email [email protected]. Visit our website at
https://ibcode.com/Downloads_Articles.html for an archive of code
questions.
Question: A sanitary (drainage) tee can only be installed
A. Horizontal to Horizontal B. Vertical to Horizontal C.
Horizontal to VerticalD. Vertical to Vertical
Code SectionsPlumbing Code 706.3 Table 706.3 IRC P3005.1 Table
3005.1Answer:OneofthemostoftennotedcodeviolationsistheimproperplacementofSanitaryTee's,Wye&1/8Bendsand
Combo's.
Asanitaryteemaynotbeinstalledonitsbackwiththesideopeninginaverticalposition.Thereasonisthatthewastewillhitthebottomofthehorizontalpipeandsplashbackupstreaminthehorizontalpipe.Thiscanleadtosolidsbeingdepositedontheupstreamsidethatwouldcauseaclogintheline.WhenconnectingaverticaldroptoahorizontalrunyoumustuseeitheraWye&1/8bend(45deg),oraSanitarycombo,(AcomboisacombinationWye&1/8bendreadymadeinonefitting).Thepurposeistoformalongradiusbendtoinsurethewasteisdirectedinthedownstreamdirectionasitentersthehorizontalrun.
Whenconnectingahorizontalrun,suchasawastearmtoaventstack or
vertical riser, you must use a SANITARY TEE. The use of acombo in
this position would put the vent stack inlet well belowthe
horizontal pipe and causes a restriction that prevents vent airfrom
getting into the horizontal line.
NOTE: This only applies to the drainage system - Sanitary Tees
are permitted in the venting system.
Code Questionof the Week
August 24, 2010
Slide Number 1
