Trap Cover on vent stack?

Is the installation of a trap (apparently used as a rain guard) for a plumbing vent stack prohibited? This is for kitchen sink and dishwasher. Not sure why owner placed it on this one vent.

ventstack 011 (Small) (Small).jpg

??? I wouldn’t due this in my part of the country(WI/MN) due to the increased chance of freeze-up in the winter.

Good point Michael. I know there are minimum vent size requirements for this reason. Any inspectors located in the Southeast have anything to say about this config.? The trap may easily be removed.

If a vent is installed correctly any rain water that enters it will go out to the sewer main. This is wrong and may cause some down flow of sewer gases into the house.


Is that PVC pipe connected to ABS pipe?

PVC pipe should only be used underground.And this is wrong I agree with previous post about freezing.

It’s very common to have it poking through the roof in this area.:shock:


I did not know that! In Toronto it is only used underground.



Yes Mario, PVC is the predominate material used here for drains and through roof vent material. ABS is a distant second. Only a handful of contractors continue to use it.


Is it the cost? Is PVC less expensive?


Mario, that’s a good question. I don’t know which costs more or which is better for the application. One experienced plumber uses it to merely distinguish himself his work from the work of others. That seems kinda silly.