# Hoarfrost and my vent



## fixitright (Jan 5, 2012)

This is definitively not a California problem,

Cold spell, -20 and my tub is burping when the toilet is flushed.

Other toilet on a different vent is not burping that tub.

I seldom use the tub that is burping so I ran it to fill the trap, still burps.
Other winters, no problem. No signs of a blockage.

This is really no big deal but could frost close a vent? 

No way I'm going on my steep, pitched, full of snow roof now.
Just one more thing.


----------



## GAN (Jul 10, 2012)

Absolutely can. In Illinois the minimum VTR is 3" and must start 12" below the roof line and protrude 12" beyond the high side of the roof penetration.


----------



## OpenSights (Mar 23, 2015)

Same here in Michigan, 3", 12" above and below. I've personally never seen it, but up north I can see it happening. 

Outside the box thinking, is there any way to open a clean out and allow warm/hot air to slowly rise in the stack? Not sure if it would work, but worth a shot.


----------



## Buddy (Oct 25, 2009)

I am not sure if this applies to your issue but someone here on the zone once posted that an easy way to check a venting problem other than going on the roof would be to take off the trap on the sink and see what happens. I thought that was a great idea and have actually used it once so far. Around here we usually have leaves clogging the vents and the occasional bird that decides to sit up there to keep warm and gets knocked out from the methane and falls in


----------



## The Dane (Feb 19, 2015)

Here in northwest Minnesota we have a minimum VTR of 2" and in my own house I have to clear snow/ice of my vent a couple times a winter. The warm air from the vent inside the house rises up and out but can easily turn to ice at the end of the vent and clog it with ice when it is so cold. 


Sent from my iPhone using Tapatalk


----------



## Master Mark (Aug 14, 2009)

our code here in indiana says you only need a 1 1/2 vent going out the roof and only one is required for the whole barn if you choose to tie them all together.........of course they are beginning to freeze solid right now... you can go down the streets and see the snow cones beginning to form on many of them.... 

I dont understand why they made it so lax here but I guess they figure it will eventually thaw out


----------



## rwh (Dec 17, 2014)

Like gan said, 3" minimum through roof. Tomorrow warm up after first good cold? Now we find what froze.


----------



## tim666 (Mar 11, 2014)

When hoarfrost is an issue here quite often we will cut the vertical section in the attic to look up through and clear it from there


----------



## Fatpat (Nov 1, 2015)

Hey it is 65 and freezing here in so cal!


----------



## The Dane (Feb 19, 2015)

Fatpat said:


> Hey it is 65 and freezing here in so cal!




65 and freezing  its a high of 30 here and a few days ago it was a high of -25 so 30 is a nice warm day here. 


Sent from my iPhone using Tapatalk


----------



## Master Mark (Aug 14, 2009)

its above 40 here now , all the snows melting off 
so the all the 1 1/2 vents that were frozen over are beginning to thaw out fast..


just wait long enough and they will correct themselves.


----------

