Horizontal Wet venting that is dry

[Levi]

I have noticed a trend....many of the issues with my folks plumbing seem to be a misapplication of Horizontal Wet Venting, which is allowed in FL.

1st example, in each bath, he has a 3" standalone vent, which turns horizontal before other fixtures tie in (the other fixtures do not have their own vents). That leaves a short horizontal dry section in the vent. Is that wrong because it is horizontal and dry, and would it be right if it was wet? Theory being that if there was a sink there instead of a dry vent it would wash the pipe?

 

[frodo]

it would be legal if the take off from the main was rolled up

that way, if the sewer backed up a solid could not enter the dry section,dry out and cut off the vent

the base of the vent shall be washed

 

[Levi]

"The base of the vent shall be washed" makes a lot of sense. Does that appear in Florida code or IPC anywhere?

 

[phishfood]

I BELIEVE that a rolled up flat dry vent is OK under UPC. I am certain that it is not OK under Florida IPC.

Levi, you are correct in your understanding what the intent of the code is.

 

[frodo]

a flat vent under upc is not allowed

it must be rolled. no exceptions

 

[Levi]

So I'm hearing the term flat vent and they are not allowed, but in florida horizontal wet vents ARE allowed.

So to clarify, does this look like a horizontal wet vent design......but wrong because the vent goes horizontal before it gets wet
Or does it look like he was trying to do something different altogether like circuit venting. (The lavs each have vents, these standalone vents serve only tub and shower)

It is too late to fix this, just wanting to understand better for future reference in case something fails. If it is compliant, I want to know, if it is not I want to understand why, maybe use that info to compel the GC to warranty the work

 

[Levi]

I spent the last four hours reading the code, the references that would explain this are a little vague. Here is a link to Florida Residentiial Plumbing code Venting chapter if anybody is interested

http://floridabuilding2.iccsafe.org/app/book/content/2014_Florida/Residential Code/Chapter 31.html