Snow over Plumbing vent pipe???

[Bill Anglin]

All right guys, I got one for ya. Up here in Washington when there's snow on the roofs. I'm used to seeing the snow melted around the plumbing vent pipes. This one is covered. Is this an indication that the plumbing waste is not venting properly? The plumbing drains were slightly slow to drain but no gurgling. Thanks for the help.

[Jerry Peck]

Is this an indication that the plumbing waste is not venting properly?

Yes, that is an indication of blocked venting.

Also, that is an indication that the vent is too short as it is supposed to be at least 6" taller than the snow load depth.

[Mike Lamb]

Yes, that is an indication of blocked venting.

Also, that is an indication that the vent is too short as it is supposed to be at least 6" taller than the snow load depth.

I did not know that. What is the reference? Here in Chicago the plumbing stacks never stick out of the roof more than 6 to 8 inches.

How old is that snow? With the snow, that roof is probably too dangerous to walk on so I'm sure you did not look down the vent with a flashlight.

It might be blocked. It might not be. It could take a while for the warm moisture in the vent to melt the snow above it.

[Jerry Peck]

I did not know that. What is the reference? Here in Chicago the plumbing stacks never stick out of the roof more than 6 to 8 inches.

Mike,

That requirement is in the IRC, not sure if it is in the Chicago Plumbing Code, I tried logging into the Chicago Plumbing Code online and all I could get where the articles and section numbers, no section text.

[John Kogel]

That snow didn't all fall in one day, lads. Every time it snows a couple of inches, a working vent would melt the snow away. Normally, the snow will melt at the vent pipes first.

[Darren Miller]

In New Jersey, the vent must extend at least 6 inches above the roof on the high side (National Standard Plumbing code).
If a vent is too high around here, it can frost over resulting in a blocked vent.

[Raymond Wand]

No avalanche guard above vent to stop sliding snow from damage vent, and thats not a proper vent boot for a metal roof.

Also appears vent is on leeward side of roof - prone to snow drifting.

[Jerry Peck]

In New Jersey, the vent must extend at least 6 inches above the roof on the high side (National Standard Plumbing code).
If a vent is too high around here, it can frost over resulting in a blocked vent.

Which is why the IRC calls for increasing the size of the vent where in freeze conditions, that prevents just what you describe. Thus the answer is not 'making the vent shorter to prevent freezing up, but which will allow snow depth to be higher than the vent', the answer is to 'increase the height of the vent above the snow load depth and increase the vent size to help prevent frost closure'. Many times the codes are compromised by the interested parties (call those people 'contractors who try to cheap out') and the "minimum code" ends up being even more minimum ... "more minimum"?, how about 'becomes less' ;) .

[Phil Gould]

The Chicago Plumbing Code reference is in section 890.1430 a) Roof Extensions: "Extensions of vent pipes through a roof shall be terminated at least 12 inches above such roof unless a roof is to be used for any other purpose than weather protection."

[Jerry Peck]

The Chicago Plumbing Code reference is in section 890.1430 a) Roof Extensions: "Extensions of vent pipes through a roof shall be terminated at least 12 inches above such roof unless a roof is to be used for any other purpose than weather protection."

"unless a roof is to be used for any other purpose than weather protection", in which case the vent must be at least 7 feet above the roof, correct?

Now consider what that really says: "unless a roof is to be used for any other purpose than weather protection" ... consider that the roof has mechanical equipment on the roof - that roof is being used for "any other purpose" "than weather protection" (it is used for the installation, servicing, maintenance, and inspection of the mechanical equipment) ... :cool: ... how high should the plumbing vent terminals be then? :) (Hint: The code tells you the answer. ;) )

[Robert Ernst]

Just have them put a cricket vent on it and that will protect it. There is no way practical to put a vent 6" above the snow line in places around here that get lots of snow. The pipe would be in the trees until the sun turned it into a candy cane or the sliding snow rips it off the roof.

[Harry Janssen]

Rarely see a vent pipe blocked with snow,unless it is to short,easy fix,if it is.

[Jim Hintz]

Here's one I found a few weeks ago and yes I was on an icy roof, just not on the shady side.

[Ken Amelin]

Looks like you folks have pictures of copper thieves. Someone is cutting all those vents short to the roof.

[BridgeMan]

Or even cast iron thieves. The drug bums will steal anything for some "fix" money.

[Rich Goeken]

No avalanche guard above vent to stop sliding snow from damage vent.....

Haven't heard that term before. Got a picture?

[Raymond Wand]

Also
Snostop Snow Guards (http://www.roofersworld.com/store_snowguards.htm)

[BridgeMan]

Kevin,

If the green metal roof pic you submitted is on a place you inspected, I hope you made a recommendation for the buyer/seller to come to an agreement on who should pay for tightening all of the fasteners. Even though the photo is a bit blurry, I think most of the screws appear to be projecting too high above the metal, and could easily be snugged down a full turn or two. When I lived in Colorado, our metal roofs (log house and separate garage/shop) would require tightening every second year, without fail. Temperature swings probably causing them to back out over enough time (with an occasional few on the sunny side actually showing screw threads under the washer heads).