• Welcome to The Building Code Forum

    Your premier resource for building code knowledge.

    This forum remains free to the public thanks to the generous support of our Sawhorse Members and Corporate Sponsors. Their contributions help keep this community thriving and accessible.

    Want enhanced access to expert discussions and exclusive features? Learn more about the benefits here.

    Ready to upgrade? Log in and upgrade now.

2" ABS vent pipe in garage fire wall

Rio

Silver Member
Joined
Mar 31, 2010
Messages
224
We have a residential project that has a garage wall next to the addition. We have 5/8" gyp. board on that common wall. There is a washer and a dryer in the garage. The contractor has run a 2" ABS vent through the fire wall into the attic above the addition, and apparently there is an ABS drainage pipe going through the fire wall also. The inspector says this has to be metal.

Looking in the 2007 CBC (basically the same as the IBC), in Section 406.1.4, in part 2 it does say that "ducts penetrating the walls or ceilings separating the dwelling unit from the garage shall be constructed of a min. of 0.019-inch sheet metal" however the ABS is not a duct. If we do need to have metal on it could we wrap the section of the ABS with a sleeve of the sheet metal?
 
Typically, the plumbers around here (SOCAL) transition from ABS to cast iron pipe/fire caulk at the garage penetrations.....
 
Build a box around it, install 5/8" drywall, tape and mud?

Wait, better check with the home owner first!

pc1
 
Rio,

Not sure what codes you are looking at but;

A vent and/or drain is not a duct; it's part of the plumbing sanitary drain system.

Uncle Bob
 
Last edited by a moderator:
Thanks for the good suggestion mtlogcabin and everyone else's response. Could I impose on you again to elaborate on 'the F&T ratings'?

Uncle Bob, I mentioned that the ABS is not a duct but it was the closest thing I could find relating to an object penetrating the fire wall mentioned in the IBC/CBC. Any suggestions on where specific information is in the code book regarding drains penetrating fire walls?

Thanks again to all for getting back to me on this.
 
Last edited by a moderator:
Rio,

Membrane penetrations IBC 712 talks about your F rating and steel, ferrous or copper pipes. It also says other listed materials and methods. Just put an Intumescent Fire Collar on it and it's a done deal.
 
F RATING. The time period that the through-penetration firestop system limits the spread of fire through the penetration when tested in accordance with ASTM E 814.

T RATING. The time period that the penetration firestop system, including the penetrating item, limits the maximum temperature rise to 325°F (163°C) above its initial temperature through the penetration on the nonfire side when tested in accordance with ASTM E 814.
 
Like Kevin and MT said, put an intumescent fire collar on it and you're done, OR you can also just change out the penetrations to cast iron.
 
Thanks for the great information mtlogcabin and thanks to every one else for helping. HAPPY THANKSGIVING!
 
Back
Top