Thread: DWV stack height

How would you report on this?
Is there a minimum height for vent pipes?

Any help would be greatly appreciated.
Thanks
Bruce

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Originally Posted by Bruce Hutton

How would you report on this?
Is there a minimum height for vent pipes?

Any help would be greatly appreciated.
Thanks
Bruce

6" above the roof, as I remember.

6" here as well...

12" in Minnesota.

6" min., according to the 06' IRC.

I'd also report that the boot flashing is not installed properly.

Bruce
According to the IRC the vent should extend at least 6" above the roof or 6" above the anticipated snow accumulation. This needs to be reported that the vent needs to be extended accordingly and a properly installed flashing installed.
Bruce

12" above the high side of the roof in Illinois

Is there any difference in the height requirement when the vent is in close proximity to a side wall?

The flashing is inproperly installed, and the IRC requires 6".. ...I agree as well.

Hey Bruce

The 2009 Uniform Plumbing Code (906.0)---The Vent pipe should terminate not less than 6" inches above the back side of the roof and one foot from any vertical surface. Rich Aldridge

The 2006 IRC and all previous versions of the Code that I can recall address this topic as follows:

P3103.1 Roof extension.

Open vent pipes that extend through
a roof shall be terminated at least 6 inches (152 mm) above the
roof or 6 inches (152 mm) above the anticipated snow accumulation,
whichever is greater, except that where a roof is to be
used for any purpose other than weather protection, the vent

extension shall be run at least 7 feet (2134 mm)above the roof.

In addition there a specific requirements for distances from windows and other intakes to the building.

P3103.5 Location of vent terminal.

An open vent terminal
from a drainage system shall not be located less than 4 feet
(1219 mm) directly beneath any door, openable window, or
other air intake opening of the building or of an adjacent building,
nor shall any such vent terminal be within 10 feet (3048
mm) horizontally of such an opening unless it is at least 2 feet

(610 mm) above the top of such opening.

IRC requires 6" min height. Also I would report the shingle coverage at the pipe flange is incorrect. If you check the NRCA website at National Roofing Contractors Association you can find standard details for pipe penetrations of shingled roofs.

Your best first reference would be the Illinois Plumbing Code (or Chicago's code should that be the case). Protection from freezing, snow heights, walls, etc. Additionally referencing the approved materials for Venting materials. Next the local municpalities or county's (should it be unincorporated area) local ammendatory restrictions. Then and only next, any further requirements of the local building, residential, or property maintenance codes adopted by the ILLINOIS locality, as compared to developed length of the stack vent, proximity indoors from the roof deck, proximity to other vents, exhausts, mechanicals, windows, parpets, walls, and in conjunction with slope of roof, etc. As you would apply the requirements as they advance to more restrictive, not less (or more permissive) as they progress.If your location was slightly more specific, since there are more than one geo zone in "Illinois" and plumbing rules are different Chicago, vs. rest of the State, and local jurisdictions adopt building, residential, and property maintenance codes with their own unique ammendments, could be more specific.

6" according to "06 IRC P3103.1
I recently did an inspection where the previous owner had sawed the vent pipes off even with the top of the rubber boot. You guessed it. Inside the attic where the vents exited through the sheathing there were moisture stains with high moisture content.

P3103.1 Roof extension.
Open vent pipes that extend through
a roof shall be terminated at least 6 inches (152 mm) above the
roof or 6 inches (152 mm) above the anticipated snow accumulation,
whichever is greater, except that where a roof is to be
used for any purpose other than weather protection, the vent
extension shall be run at least 7 feet (2134 mm)above the roof.

MMMM! Codes can be so ambiguous. So how does one determine what the anticipated snow accumulation may be? (anything that the AHJ says??) Talk about a problem in the making.

In regards to anticipated snow amounts, each state has a standard that they go by. Colorado will vary depending on what area of Colorado your in for example. So local codes should cover these anticipated heights.

That is what I use to seeing. NC will have far less than the northern states.

Thanks alot guys...I really appreciate all the help!
Have a great weekend!
Bruce

Hi, ALL &

How about:

"short"

"hidden"

"puny"

"embarrasing"

Anyone should get the idea...


CHEERS !

Bruce Hutton,

I have to disagree with all the posters who claimed the minimum height above finished roofing materials was six inches (or seven feet above for other than weather protection only roofs) as pointed out previously, you indicate on your profile your location is ILLINOIS, the minimums are greater heights.

I looked up some of your prior posts, and found where you indicated you worked in a greater community area 70,000 pop or so, so obviously you aren't in the City of Chicago.

The absolute minimum in Illinois outside of the City of Chicago, is 12"above, assuming the developed length vertical is already 80%+, there is sufficient developed vertical height from the next lowest joint or connection, offset, horizontal branch, and height from next lowest flood rim, trade size transition (increasers) relative to underside of roof deck, etc.; there are no nearby walls, chimneys, vent/air/mechanical entrances or terminations, doors/windows, etc. within proximity, adjacent/adjoining property openings, and the roof is for weather only, and the diameter enlargement has taken place within the envelope, the pressures, adjustment factors are sufficient. The venting material also makes a difference. There are oftentimes when the height MUST BE HEIGHTENED. 12" is not necessarily the APPLIED minimum height for your particular situation.

If the roof surface is being used for other than just weather protection (such as to support equipment, a nearby deck, garden, etc. that minimum height bumps up to 7-3/4 feet or so, (or more) above.

Further, there are different regions in Illinois regarding snow depth/cover/loads, to wit other building codes and local adoptions/ammendments address.

Outside the City of Chicago, no local "home rule" can override or conflict with Illinois state plumbing code except to further limit/impose restrictions, they can NOT be MORE PREMISSIVE or reduce a minimum - only "raise the bar", so to speak. Subpart K (Sections 890.1410-890.1580) 1460, appendix A table K, and the better part of appendix K of Part 890 "Illinois Plumbing Code" go into further detail. Local ammendments can make further restrictions. You should be familiar with local "home rule" adoptions for those areas you inspect in.

Following is a (clickable) interactive linking to the Sections listing index (hyperlinked to sections) from illinois general assembly website to the Joint Committe on Administrative Rules area - i.e. the Illinois Administrative Code, Title 77 (Public Health), the supplied link takes you to the sections listing for PART 890 (Illinois Plumbing Code - 2004) of Subchapter r (Water and Sewer), of Chapter I (Department of Public Health), of Title 77, last amended at 28 Ill. Reg. 4215, effective February 18, 2004; and at 29 Ill. Reg. 5713, effective April 8, 2005.


PART 890 ILLINOIS PLUMBING CODE : Sections Listing

See especially Table K of Appendix A, Illustrations D and E of appendix K (clickable links identified below):

Table K of Appendix A:

Section 885


Illustration D, Appendix K:

http://www.ilga.gov/commission/jcar/...ZZ9996kdR.html

Illustration E, Appendix K:
http://www.ilga.gov/commission/jcar/...ZZ9996keR.html

If you were in Michigan, the MRC would apply, P3103.1 Roof extension. All open vent pipes that extend through the roof shall terminate at least 1 foot (305 mm) above the roof, except that if the roof is to be used for any purpose other than weather protection, then the vent extension shall be run not less than 7 feet (2134 mm) above the roof. Note these are minimums.

Not unusual to find

What problem is it causing

The IRC does not state a specific height above the roof, the IRC states (see bold and underlining):
- P3103.1 Roof extension. Open vent pipes that extend through a roof shall be terminated at least 6 inches (152 mm) above the roof or 6 inches (152 mm) above the anticipated snow accumulation, whichever is greater, except that where a roof is to be used for any purpose other than weather protection, the vent extension shall be run at least 7 feet (2134 mm) above the roof.

Many forget about the requirement in bold, and even more people forget about the requirement which is underlined.

And what that unammended portion of the IRC says doesn't mean a hill of beans for the Original Poster who gives us his profile location as in Illinois, and the Illinois Plumbing Code requires greater minimums. AFAIK Illinois has not adopted state-wide uniform building codes - Illinois operates on the Home-Rule System.Illinois has a statewide plumbing code (Chicago excepted), that may not be usurped by local adoption of other codes, it may only be "enhanced" as to provide greater restrictions, not be in any way more permissive. More than one code speaks to the issue for the OP, and the most restrictive applies.In Illinois it is 12"+ and 7feet8inches+, and has further provisions regarding proximity and protection from freezing. The vent stack is part of the DWV plumbing system. Roofing codes do not trump plumbing codes in Illinois. If the developed vertical is not at least 80% it must be increased to meet that provision as well.