What is normal size vent pipe for plumbing..?

[Tim Fitzgerald]

Plumber is coming to make my vent stacks in new shop (metal ). Says that everything will tie in to 3" and go through wall instead of roof. Isnt this a little large, I have yet to see a big ole honkin 3" hole in any roof. Cant this be reduced down to 2"....? What does code say about all this? and also, if he does go through wall, shouldnt the cover be like a dryer vent type and do they make those with the maleable type aluminum / calked gasket like they do for the roofs....?

I need some opinions on this one because I am clueless about plumbing. I live in red neck central and want to be sure that there are no jeff foxworthy looking **** on my shop...

Thanks in advance any help.....

 

[Mustang51js]

I'm pretty sure 3 inch is the minimum, most places are doing 4 inch now.

 

[Big Bad Dad]

3 inch has been the code standard for years.

 

[larry_g]

I think your like me , used to seeing many vents in the roof, one for each fixture drain. I believe for the most part modern construction each fixture vent is run to one main vent that is vented to the outside.

lg
no neat sig line

 

[6t7gto]

http://www.terrylove.com/forums/forum.php

 

[Bigwhite11]

The minimum size should be 3" or the same size as the building drain (if the building drain is 4", the vent needs to be 4"). Each state is different though, but that is common practice areond here.

 

[conrad1972]

I just got done doing a little work on mine and it went from 4" up to 6" out the roof. I don't think you have to worry about frost too much down.

 

[Nighttrain]

How high up the wall will it vent? Reason they are on the roof is because they stink.

 

[texas webb]

Are you venting for a toilet as well?4" would be better,if you are going
thru the wall make sure top of vent stack is at least1-2ft above the
highest roof elevation.

 

[dledinger]

It is based on the number and type of fixtures and calculated by the DFUs assigned to those fixtures for your application.