Dry horizontal vent below the flood level of a fixture........

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michael lombardi

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Hello all,
I'm new to this forum , but have been in this trade for 45 plus years. I'm involved in a discussion on another forum ( ask.com / plumbing) and need help confirming a very basic venting flaw that the sites experts claim is normal and accepted as standard best practice......
 

Smooky

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What are they saying and what do you think? Also the code is different in different cities, states countries etc so you could both be right depending on what the code says in your or his area.

In NC it says this:

905.4 Vertical rise of vent. Every dry vent shall rise vertically
to a minimum of 6 inches (152 mm) above the flood level rim of
the highest trap or trapped fixture being vented.
Exception: When vents for interceptors and isolated floor
drains are not located near an adj acent wall the vent must
rise 6 inches (152 mm) vertically before turning horizontally
and continuing to the nearest wall. For cleaning purposes
a cleanout the same size as the vent shall be installed.

905.5 Height above fixtures. A connection between a vent
pipe and a vent stack or stack vent shall be made at least 6
inches (152 mm) above the flood level rim of the highest fixture
served by the vent. Horizontal vent pipes forming branch vents,
relief vents or loop vents shall be at least 6 inches (152 mm)
above the flood level rim of the highest fixture served.
 
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hj

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Years ago we were doing several bakery additions, which were all basically the same, but each needed its own permit. After doing several of them I went in to get a permit for the next one. The drawing was rejected because of venting, so I asked them HOW I should do it. They said, "see that guy over there? He will show you how it's done", so I went over there. When I explained the problem he proceeded to draw a system with ALL underfloor vents from the floor drains. I told him, "You cannot run vents like that", and he explained that you CAN do it according to the "new code". I took the drawing to the permit desk and the rejected it. They asked, "Who drew this", and I said the guy over there, so they said have HIM issue the permit. I did and since we had already installed the system according to the 'old code", but the revisions would be minor, so I told him, "Send the inspector over". We make the revisions, the inspector came and REJECTED the installation because of the flat underfloor vents. I showed him the drawing from his OWN department. He then called his supervisor and told him, "We have this installation with flat vents under the floor. He has a drawing dated this morning drawn and approved by our department". The supervisor said, "Have the person who issued the permit, approve the installation". I told the inspector, "As soon as you walk out the door, concrete is going into the floor, so give me the green tag". He did, we poured the concrete, and 30 minutes later the inspector was back and said, "As of this minute, we are back on the old code". Six months later we were doing another job and the same inspector showed up. He said, "Aren't you the same guy who did the bakery a few months ago?" When I said yes, he said could you make a drawing of the drain system because ALL of the paperwork for that job has disappeared.
 

Terry

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I did seven meat markets for the same store, all over the Puget Sound area.
Same basic plan, seven permits. I met with seven different inspectors that assured me that their way was the only way. Everybody had their own tweak on the code.
If you keep the revents to 6" above flood you always okay. Some places now allow some horizontal wet venting, but this was back in the 80's.
 
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