Sewer Gas exposure through vent pipes on roof

Miscellaneous Inspection Topics AskNACHI.org Questions
1

Hello,

I live in a unit at the top of a walk-up apartment building (5 stories). I have access to the roof terrace as it is connected to my unit. There are several vents on the roof, naturally, yet I wonder if they pose a health risk to myself and my family given that sewer gas comes out into the air here and we are there to smell it. I can hear the flushing of toilets through each individual vent pipe and from time to time the smell of sewer gas (methane etc.) Can I assume that the concentration is too minute to affect us especially given that it is in the open air?

Thank you very much,

Nick

2

Hi Nick

In regards to your question, there are a number of complexities in regards to how diluted the fumes/smells etc may be on your roof deck.

Most building standards that I’m aware of require the vents to terminate at least 7’ above a roof used as a deck, likely due in part to your question.

Nachi.org has an article that is related to your question, feel free to take a look https://www.nachi.org/sewer-gases-home.htm?loadbetadesign=0