# Frozen Vent Pipe



## Ratchye

Hello smart plumbers,

Due to very cold weather, along with a relatively short vent stack too close to the apex of our 12/12 roof, we have a severely frozen vent pipe. Ugh.

My husband tried today to rope up and get on the roof to poor some water down it and add an extender with a 180 bend to prevent further problems, but couldn't even get a rope over the rooftop with the great pitch. 

It is about 3 stories up....so no going up on the roof w/o a rope. Our neighbors recently had a house fire because they used heat tape on their pipe.... :furious:

Looking for some good ideas as to how best (and safest) to get this unfrozen so we can resume using our plumbing system.

Thanks in advance for any help!!!

Jen


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## Tom Struble

i hear stories of homeowners falling off their roofs all the time
it can be dangerous up there even for a pro
you should hires a licensed plumber let him take the risk 
just my opinion


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## mason

Depending on the access you have to this vent pipe on the inside of your house, a strong heater with a built in blower (hair drier) might send enough heat up this pipe to melt away the blockade without any roof climbing being necessary


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## Termite

Have you had an ice storm? If not, I'm not sure how the vent could freeze. You might get into the attic and check to make sure that there is good downward pitch on any horizontal runs of vent pipe because otherwise water could accumulate and freeze.


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## Marvin Gardens

thekctermite said:


> Have you had an ice storm? If not, I'm not sure how the vent could freeze. You might get into the attic and check to make sure that there is good downward pitch on any horizontal runs of vent pipe because otherwise water could accumulate and freeze.


My thoughts also.

How can a vent pipe freeze???? Usually there is enough warm air going up the there to keep it from freezing.


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## Ratchye

*Definitely Frozen!*



Marvin Gardens said:


> My thoughts also.
> 
> How can a vent pipe freeze???? Usually there is enough warm air going up the there to keep it from freezing.


Well, we live in Alaska, and the last two weeks the temperature has hovered around -25. My husband did make it up on the roof (roped in), and found that there was about 2-3 inches of ice. Interestingly, the layers of ice had formed inside, with concentric rings, much like what you would find on the inside of a tree.

He poured water down it, then immediately put a 2 foot extension on it and topped the extension with two 90 degree elbows, so now the pipe vents down towards the house. The husband then climbed down the roof safely:thumbup: and all has been well. Of course, we've had a 50 degree increase in temps so that will help! 

Thanks - Ratchye


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## majakdragon

I have seen this before. Sometimes caused by spiderwebs in end of the vent, and then condensate freezes onto them. In Ohio, even though smaller vent piping was allowed, the minimum for the last 3 foot going through the roof was 3" pipe. This was to prevent the problem you had.


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## Ratchye

Yep - our pipe is 3". I hadn't thought about the spiderweb idea...hmmm....If anyone in colder climates has experienced these problems and has great ideas, please let me know!


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## Chemist1961

I have been reading up because last Saturday nite all 3 of my toilets stopped flushing. There is a heated vent stack on the market, designed and built in Ontario.
I have also read that an extension beyond 8" on the short side is too much and will likely refreeze more easily????. This info was from Central Canada where the temp can hit -55. There are suggestions to insulate your pipe right to the roof line and fully within the attic.
I checked mine by cutting in inside the attic and installing a Fernco coupler for NEXT TIME. Seemd to me if I need to thaw anything I could do it just as well from the attic and a whole lot safer.:yes:but I didn't find any ice , perhaps because I got there too late, mid day Sunday after looking elsewhere for blockage. I'm still searching for answers but flushing again.


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## Chemist1961

Sorry believe it or not IT's Called Arctic Vent by Heatline


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## johnjohnson1957

I live in Montana and yes it does get cold here. I have the same problem with the plumbing vent pipe freezing up. THe vent pipe passes through 8-9 feet of unheated attic space before exiting the roof where it continues another foot or so. So far this winter I have had the vent pipe freeze 4 times. It is the warm moist air in the plumbing vents that gradualy coat the inside of the 3" vent pipes until they are closed and not falling snow that blocks the vent pipes. So far this year I have been on the roof twice cleaning ice out to allow the pipes to vent. Another solution is to pour boiling water down the vent pipe. Problem with these two idea is you have to climb on to the roof. Not a great idea when it is ice and snow covered.

To stay off the roof I cut the vent pipe in the attic space and rejoined the two end with a rubber bushing (available at any big box hardware store) I can now work on ice blockages from the relative safety and comfort of the attic vice being on the roof. I also have wrapped the vent pipe in insulation in an attempt to keep the vent pipe as warm as possible so it will vent rather than freeze up. This has had mixed results in that I have had to clear ice blockages from the vent pipe two more time since cutting the vent pipes. Couple of cautions with this idea. It is important not to allow your plumbing vents to vent into your attic. Doing so will eventually make a mess (moisture freezes and eventually melts in the atic) not to mention do serious moisture damage to your attic framing. Another option along this line is to insert a PVC clean out fitting in the plumbing vent pipe. This way you can just remove the clean out plug and then snake out the ice.

I have heard of inserting heat tape into the vent pipe (something the manufactures don't recommend) but have not tried it. 

I have heard of (and tried) inserting a long 1" copper pipe into the vent pipe (you fix a T-fitting on the end and then fix short pieces of pipe to the T to support it on the top of the vent pipe). I assume the idea here is to ensure the copper pipe reacheds into the heated part of the house and then it transmits the heat up the pipe helping keep the vent from freezing. FYI: They did not work or me. 

Come spring time I plan to spray paint the vent stacks black. This way they will be beter at absorbing the sun's heat and help keep the vent open. Meanwhile I will continue to make trips tothe attic to bang on the pipes or to snake out the ice out. 

I am considering filling a copper pipe with auto antifreeze mixture and then capping it so it is a closed system. Then I'd attach heat tape to it and hang it in the vent pipe. The reason for the antifreeze is to give the pipe some thermal mass to increase the odds it actually hold some of the heat the heat tape produces.


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## Chemist1961

JJ,
Wow I used to live north of you I remember that cold. -50 without the wind, square tires, stirred the stickshift in my 5 speed before I could release the clutch......Seems to me years ago I heard straight antifreeze will also freeze where diluted won't or maybe it boils faster... Don't recall which. Anyway check out the properties before you fill the tube.


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## joebart

Hi all, how about installing foil insulation in the roof rafters in the attic. I am learning that this should keep some of the cold out of the attic and possibly transfer heat from the sun to raise the roof surface temp. 

If you insulate the vent pipe you may insulate the pipe from any heat that may be developed within the attic. 

Okay just my 2 cents!
Good Luck
Joe


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## Reilley

joebart said:


> Hi all, how about installing foil insulation in the roof rafters in the attic. I am learning that this should keep some of the cold out of the attic and possibly transfer heat from the sun to raise the roof surface temp.
> 
> If you insulate the vent pipe you may insulate the pipe from any heat that may be developed within the attic.
> 
> Okay just my 2 cents!
> Good Luck
> Joe


Ideal attic temperature is close to outside temperature, so insulating as it passes through the attic is not a bad idea.

Why not run a heating cable around the pipe and plug it in when you notice the smell of methane in the house? 

I just pull out the ladder and pour some hot water down my vents if they freeze. Works like a charm, although I don't have a 12/12 pitch.


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## joebart

Reilley said:


> Ideal attic temperature is close to outside temperature, so insulating as it passes through the attic is not a bad idea.
> 
> Why not run a heating cable around the pipe and plug it in when you notice the smell of methane in the house?
> 
> I just pull out the ladder and pour some hot water down my vents if they freeze. Works like a charm, although I don't have a 12/12 pitch.


You seem to missunderstand what I typed. Please read it again before continuing. Do not allow the vent pipe to vent into the attic. It MUST exit the roof and be at least 18" above the roof surface OUTSIDE of the house!

Using heat tape on PVC pipe will burn down your house in a matter of time. 

Insulating the roof rafters with a foil insulation will keep the attic at a warmer temp than the outside during the winter time and cooler in the summer. The heat within the attic will keep the vent pipe warm enough to possibly stop it from freezing during those cold months.

So when you climb onto your roof full of ice with a bucket of warm water and make your way across the slippery roof you don't think how dangerouse that is? You don't think of your family's wellbeing if you were to fall and kill yourself? How about when you finally make it to the pipe and I bet you stick you nose right into that pipe to look deep into it to see where the ice has bulit up. So you see the ice and then finaly pour warm water into the pipe and as you pour the water your nose is still over the pipe and once the ice melts you inhale that huge slug of methane gas as well as other sutff that has been collecting their for days. 

Don't you think its better and safer to fix a potential problem once the cause is known? Seems like your looking for your 15 minutes of fame. If you continue this method of going up on the roof I am sure to see the OSHA video of your dead body on the ground with a caption saying "Frozen Vent Pipe Got Him"

Please be safe.


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## brokenknee

If you read the label on the heat tape, it states to be used for water filled pipes only.

As stated earlier ideal attic temperature is as close to the outside ambient temp as possible. Having it warmer will cause condensation which in itself brings a whole new set of problems much worse than frozen pipes.

Insulating the pipe itself would be OK.


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## joebart

Hi Brokenknee, hope your knee is better. I agree that if the attic is not insulated properly condinsation will damage the whole roof structure and work its way down the walls totally destroying them. I guess I should have included pictures. Anyway so insulating just the pipe will possibly stop the vent from freezing? 

I am loving these forums because with each reply brings up different thoughts. 

So lets say the vent pipe is not insulated since that is the normal installation and the pitch is proper. Any moisture making its way up the vent will collect on the interior pipe walls and pool enough to become heavy and drip down the pipe. If it is cold enough in the attic the moisture can freeze within the pipe in the attic and not necessarly where the pipe goes through the roof. Then as more moisture makes its way up the vent it can compound onto what is already frozen and eventually clog the pipe. WOW, that is some chunk of ice lol.

So insulating just the pipe will stop keep the vent pipe warm enough especially with the open end exposed to the atmosphere?

I am thinking that to totally prevent the vent pipe from freezing the area around the vent pipe needs to stay above 32 degrees F. This can be accomplished by installing some kind of attic insulation that allows proper venting for the roof?

As I continue on my rant, I think I will explain this to death, lol. 

Thanks Brokenknee!.


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## brokenknee

The knee is pretty good, will most likely always have some discomfort. I have been back to work since the beginning of November.

Insulating the pipe may work, it will help keep the interior of the pipe above freezing. That would be my first attempt to solve the problem.


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## Reilley

joebart said:


> You seem to missunderstand what I typed. Please read it again before continuing. Do not allow the vent pipe to vent into the attic. It MUST exit the roof and be at least 18" above the roof surface OUTSIDE of the house!
> 
> Using heat tape on PVC pipe will burn down your house in a matter of time.
> 
> Insulating the roof rafters with a foil insulation will keep the attic at a warmer temp than the outside during the winter time and cooler in the summer. The heat within the attic will keep the vent pipe warm enough to possibly stop it from freezing during those cold months.
> 
> So when you climb onto your roof full of ice with a bucket of warm water and make your way across the slippery roof you don't think how dangerouse that is? You don't think of your family's wellbeing if you were to fall and kill yourself? How about when you finally make it to the pipe and I bet you stick you nose right into that pipe to look deep into it to see where the ice has bulit up. So you see the ice and then finaly pour warm water into the pipe and as you pour the water your nose is still over the pipe and once the ice melts you inhale that huge slug of methane gas as well as other sutff that has been collecting their for days.
> 
> Don't you think its better and safer to fix a potential problem once the cause is known? Seems like your looking for your 15 minutes of fame. If you continue this method of going up on the roof I am sure to see the OSHA video of your dead body on the ground with a caption saying "Frozen Vent Pipe Got Him"
> 
> Please be safe.


Hahaha wow. Yes, as a matter of fact I love to take nice big breaths of methane prior to jumping off my slippery roof. I wasn't responding to anything you said, just the thread in general.


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## joebart

Sorry Reilley, I tend to get on the ever popular high horse and spew out all kinds of stuff, lol! thanks for putting up with me.


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## tigers41

I have a similar problm as you are descriping right now. My 2nd floor ceiling developed a water stain and when I went into the attic I had condensation build-up underneathe where the vent pipes exits the roof. I went onto the roof and the entire vent pipe was frozen. This is a double wall vent pipe that is fed by the furnance and two water heaters. Can I insulate the inside vent in the attic to help prevent this. We have had cold temperatures in Missouri but no snow at all this year, so it is mainly freezing as it comes out of the pipe. One roofer told me to replace the vent stack at the roof since he thought it was defective possibly and forcing the air onto the roof which is causing it to freeze.


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## sgtjgb

I have an unusual solution to the "Frozen Vent Pipe" problem that I wish I could say was my own but, I think I saw it years ago on some home improvement show and thought I'd never have a use for it. The problem starts with a 3 story plumbing chase 12inches by 12inches that includes a 3/4inch copper water supply through the bottom 2 stories and a 3inch pvc vent stack that runs up all 3 stories and to about 30inches above the shingles. Since the vent stack is simply a 3inch pipe that ends above the roof; it allows cold air to drop down the pipe creating a 3inch diameter column of freezing cold air through the plumbing chase. This in turn cools the air in the chase and the bottom of the water line freezes forcing me to cut through the sheetrock and hook up welding cables to thaw it. 
The solution as I see it is to add two 3inch street elbows to the top of the vent stack and a 12inch length of 3inch pvc with a strainer to prevent any birds, squirrels or other creatures from entering. What you end up with is a candy cane shaped vent that creates an air lock to prevent cold air from entering; since cold air can't rise, it's unable to go up the short side and over the hump to enter the stack, and the fairly stagnant air on the long stack side stays above freezing from the heat transfer through the walls and allows a constant slow rise of warm air to flow up the pipe tending to push the cold air out. 
This problem happened in January and I've been letting the faucet trickle to prevent anymore problems this year since running water won't freeze and I'm 59 and not about to roof climb in the cold. I'm wondering if anyone has ever heard of this method and could give me some verification. I can't believe I dreamt it in my sleep but, really can't remember where I saw it. Thought I would glue all the joints and if for some reason a problem developed the added pipe could be cut off.


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## der Mond

*Alaska Home-Moaner*

Any further intel on this? I just posted under the above thread in the Introductions section and then did a search and found this thread. My vent is freezing up DAILY now and driving me crazy. Has the person who started this found a solution that works?


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## der Mond

Ratchye are you still listening? I live in Alaska also and if I could get verification from you that your solution is still working it would greatly ease my mind...Mine is freezing up at -10 and we can get to -60.


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## tylernt

Company called Heatline makes an "ArcticVent" product. No idea if it's any good, though. And you'd need a place to plug it in.


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## der Mond

*Problem Solved*

Arctic Vent looks great, and a bout a grand to have one installed. But thanks for the tip.

I took everything I heard and did this: It is old double-walled metal pipe with 3 3/4 " ID; I took an 18" piece of 3" PVC and attached a wide "T". Bought a 12' length of Raychem 7W/foot heat tape and made three loops with it and squeezed them up the pipe and almost out one side of the "T" so I had basically 6 loosely flopping lengths of heat tape inside from end-to-end, slid it down the vent with the "T" perpendicular to prevailing wind to enhance a vacuum effect, and plugged it in. So far it works great, no stink and two gentle plumes of steam rising into the -20 F. night sky...:thumbsup: 

I took everything I heard and did this: It is old double-walled metal pipe with 3 3/4 " ID; I took an 18" piece of 3" PVC and attached a wide "T". Bought a 12' length of Raychem 7W/foot heat tape and made three loops with it and squeezed them up the pipe and almost out one side of the "T" so I had basically 6 loosely flopping lengths of heat tape inside from end-to-end, slid it down the vent with the "T" perpendicular to prevailing wind to enhance a vacuum effect, and plugged it in. So far it works great, no stink and two gentle plumes of steam rising into the -20 F. night sky...:thumbsup:


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## tylernt

Are you sure heat tape in direct contact with PVC is a good idea?


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## der Mond

7W/foot heat tape is a newer kind of heat tape product that carries no risk of setting PVC on fire. If that turns out to be false then I'll retract it. I'd advise you visit your plumbing supply store and ask them about it.


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## Ratchye

*Still here!*



der Mond said:


> Ratchye are you still listening? I live in Alaska also and if I could get verification from you that your solution is still working it would greatly ease my mind...Mine is freezing up at -10 and we can get to -60.


Still listening!

After "solving" the problem - multiple times, we're back to square one. We have tried:

*Insulating the pipe from bottom of attic to top, and
*Not insulating the pipe

*Purchasing two 90 degree caps (the "candy cane" method), and
*Then taking them off again

*Widening the problem vent to 4" AND dropping some serious cash to install a second 3" vent in case overload was an issue.....BUT

No luck.  We did make it through last year without too much problem - maybe Mother Nature was looking out for us - but the moderately cold Alaska temps last week (down to -15 or so) have left us in the same predicament I posted about almost 4 years ago. 

Read through the threads to see if any new inventions had cropped up, but nothing. Am now considering either the Arctic Vent OR the potential of lining the inside of the roof vent with a material that is freeze resistant (researching: extruded polystyrene foam insulation). 

Any new, great ideas out there?

Ratchye


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## tylernt

Here's my theory. The water in your traps and in the sewer main (or septic tank) is gonna be cold by human standards, but it's still warmer than ambient. So, it's gonna steam. Maybe not clouds of visible steam, but a wisp of moisture nonetheless. This warm, moisture-laden air rises. And when that moisture hits the colder section of pipe that sticks up above the roof, it condenses and freezes.

Seems like there are some options:

1. Keep the pipe above the roof 32°F or more.
2. Keep the moisture from reaching that far.
3. Use mechanical/chemical means to keep the ice from building up, or make the ice break off by itself.

#1 we've covered, typically electric heating.

#2 Maybe a flap in the pipe in the attic that closes at zero pressure to keep the moisture in and opens at either negative pressure (toilet flushed) or positive pressure (escaping sewer gas)? Probably no such thing made, and wouldn't pass code if fabricated.

#3 might be coating the inside of the with Rain-X, wax, petroleum jelly, or similar substance.


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## jagans

*Pipe*

What material is the vent pipe made of, PVC or Cast Iron?


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## jagans

*Vent*

OK since you never answered my question re type of pipe, here is what I would try, assuming you have PVC running up through the roof. Cut off the PVC at the attic floor. Install a 3 inch Galvanized Steel or Cast Iron pipe from there up through the roof. Join them with a fernco coupling You can install a riser clamp on the floor, or U-Bolt to a rafter if your close to one. My thinking here is that the cold from outside will conduct down the steel pipe so that the water laden vapor will condense somewhere inside the steel pipe, and run back down. In effect you are moving the dew point down into the pipe. 

You can buy a reducing (Increasing) coupling and use it to go to 4 inch CI instead of three, and that would also help, as the ice would have another inch to bridge the opening. It actually sounds like you have a gas appliance connected to this pipe. There is a lot of water in Propane and Natural gas that comes out when you burn it.

I never heard of sewer gas producing enough water vapor to do what you are describing, but that does not mean it cant happen I guess.


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## der Mond

Seems like folks aren't reading previous posts. Raychem 7W/foot heat tape can be bought in varying lengths and bunched up and inserted down a vent pipe the distance down through the roof insulation to where it is warmer. I just put a 3" PVC T on top and shoved the tape in one end and down the tube about 18". Problem entirely solved, I have it plugged in all the time and it will not start a house fire. It has gone from -37 to +20 in a snowstorm at present. You folks who can't imagine why a vent pipe would freeze have never experienced Alaska cold.


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## mginwyo

*Cold froze vent stacks in WY*

I have been lurking and watching this thread and others on the topic for a couple years. Having the same issue mainly with subzero temps and windy conditions. Wyoming has tons of wind and lots of cold at times too! 

Installed FJ Moore frost proof vents and had some success but froze once last year. Enlarged the vents to 3" from 2" and thought I would be done but the last week they froze again. I got up on the roof and saw light snow/frost "cap" 90% covering the openings of 2 of the 3 vents and #3 was 100% covered. We had temps drop from +60 to zero in 3 days time and have had 4 nights of subzero reaching -25 with 30mph winds. There is no sight of +32 for another few days. 

So I have been looking at a lot of ideas and it looks like success is fleeting. except Der mond is confident in his solution from his experience. 

I will be getting the no freeze tape and hanging inside the stacks. Can't do it the way he says so I think I will drill in from under the roofline and run the tape up the stack instead of down into it. Hang it from the top and seal the hole in the side of each of the vent pipes. 

Just wondering if there are t-stat cubes that will activate at lower than 35 degrees. I have no problems until zero so if I could get one that activates at 10 above I'd be happy. 

Another thought, Anyone tried one of the remote control devices like a garage door opener button used for lamps or Christmas lights inside to activate their tape? don't want to be in the attic or on the roof plugging stuff in when it stinks and is stinking cold. :laughing:

Also not wanting to leave the tape power on when it is not needed. Save power and less chance of short circuit or heating a pipe that does not need to be heated at that time...

I have 3 vents spanning 40" on a roofline so need to figure out how to get them all on with the same switch too. One power source outlet in the attic about 25 ft from the longest point so that will likely be the tap.


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## Ghostmaker

What about using a circulating pump and hot water from your hwt. Use 3/8 inch pex and wrap your vent with the tubing. Leave yourself a way to drain it down and only use when it freezes shut.


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## mginwyo

Well it might work but Seems like one problem for another with running water up to the vents. would have to Figure out a drain once you push the water up there and if it clears the vent, No way you need a flood on a floor somewhere in weather that cold... keeping the water hot enough through the pipe to get it there and do some good... Frozen water down the roof if it breaks for some reason. etc... rather have an electric on off solution I think. 

I lived in the S/W US for many years and had no clue issues like this occurred! Fun stuff!


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## Javiles

The last time we had a frozen vent pipe weeee.. OOOps sorry iam in south Florida its December and its 80+.... -25 - 55 you guys must be nuts no offense but geees, ..:thumbup: forget about the vent move Miami and lets go boating in December


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## Bob Sanders

mginwyo said:


> Enlarged the vents to 3" from 2" and thought I would be done but the last week they froze again.


Go to 4".

That's mostly what you see around here (Winnipeg, Canada) and our temps hover around -40 in January. It doesn't COMPLETELY eliminate the possibility of freezing, but it cuts it down to almost nothing.


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## Bob Sanders

Javiles said:


> forget about the vent move Miami and lets go boating in December


Nah. No offence but it gets a bit boring doing the same thing all year round. Come here though and I'll show you how to strap on some scuba tanks and play ball hockey on the under side of the ice.


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## Ghostmaker

What if we used a double wall heat exchanger and circulated antifreeze?

Now no need to drain it.


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## jag218

We installed a 'T' in the attic portion of the vent pipe. The 'T' allows access for inspection and in my case to run a drain cleaning spring-wire snake up the vent. 
Our vent had a lot a frost on the vent pipe walls, but the snake went to the top where it met resistance (combination snow-ice cap??). Using the snake like a drain cleaner I was able to bore through and open the vent. 
It's cheap, easy and in our case worked.


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## Bill723

I'm having a having a similar/same problem. I've lived in my house for 14 years, never had this problem until I had my roof reroofed last year. Now everytime the temps drop in the teens or twenties iceicles form on my vent opening at the roof and leak back through. It had to be something the roofer did or did not do. Ideas?


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## ktvr3

*really?!?*

to all you fair weather idiots that keep saying stuff like"how could it freeze" you obviously have never been to the prairie states or provinces. yesh. sometimes its -50 for weeks. that how it freezes. not everyone lives where its warm. duh:vs_mad:


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## ktvr3

Javiles said:


> The last time we had a frozen vent pipe weeee.. OOOps sorry iam in south Florida its December and its 80+.... -25 - 55 you guys must be nuts no offense but geees, ..:thumbup: forget about the vent move Miami and lets go boating in December


ummmm ya no i would rather deal with a tiny frozen vent every now and then then have to put up with hurricanes. :vs_no_no_no:


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## WhatRnsdownhill

once you get it unfrozen, either with heat or hot water, you can try making a ubend far enough from the roof line so it doesnt go under snow to prevent build up from snow and freezing rain on the inside of the pipe...if the stack is 3 or 4 inch use 2 90 degree elbows to do this..


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## Ratchye

jag218 said:


> We installed a 'T' in the attic portion of the vent pipe. The 'T' allows access for inspection and in my case to run a drain cleaning spring-wire snake up the vent.
> Our vent had a lot a frost on the vent pipe walls, but the snake went to the top where it met resistance (combination snow-ice cap??). Using the snake like a drain cleaner I was able to bore through and open the vent.
> It's cheap, easy and in our case worked.


I'm back :vs_mad: (initial thread poster) - Four years later we're having issues again. Although I have to say it's been a good (relatively warm) four years without trouble! 

I'm interested in the 'T' option mentioned above. As someone with limited plumbing/roofing/vent/etc. skills, I would imagine the 'T' would need to be capped to ensure sewer/vapor didn't vent into the attic, correct? Also, how does one ensure that sewer/vapor doesn't escape through the top and bottom of the 'T' where it connects to the existing pipe? Is there special tape that's placed at the connection?

Finally, for a 4" PVC pipe, would one purchase a 4" 'T' and a connection casing of some sort?

Thanks, again, posters. Your suggestions are appreciated!

Ratchye


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## SeniorSitizen

Install a clean out wye. Install 180° from what's pictured. A short piece of pipe with a cap at the Y.


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## SeniorSitizen

Edit time kind of sucks, but traditional clean out Y's have a threaded Y with a screw plug. I just couldn't locate a picture of one very quickly and mine is buried in the yard.


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## supers05

I see frozen vents here on the flat roofs here and it's not so cold. It's the moisture condensing and freezing over time. It starts to be noticeable around 15*f or so depending on the stack and winds. 

I'd probably use pipe heat trace. I didn't read of the post, but I did see where you mentioned about a fire. They are used all the time here in under ground garages, with appropriate fuses. They do burn out, but I haven't seen one cause a fire. (they are all wrapped in fire retardant insulation just in case.) I'm not sure what went wrong with your neighbors. 

The clean-out tee is probably a great alternative though. 

Have you tried armaflex or similar on the pipe in the attic and above the roofline? (closed cell foam insulation, specially for pipe from hardware stores) gasses warmer, longer, preventing as much condensation.

Cheers!


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## BlackTiger

In this case I think a cleanouts tee may be better than an inverted cleanout wye because the angled portion may collect water and either spill some (smelly) water into your attic or even also freeze!


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## SeniorSitizen

Good point BlackTiger.

With the T we still need a convenient access so I wonder if would it be a code violation to use a test plug with the wye.


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## BlackTiger

SeniorSitizen said:


> Good point BlackTiger.
> 
> With the T we still need a convenient access so I wonder if would it be a code violation to use a test plug with the wye.


I don't see why a cleanout tee would be less convenient access than a cleanout wye. We might not be talking about the same thing. This is what I mean by a cleanout tee.


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## SeniorSitizen

BlackTiger said:


> I don't see why a cleanout tee would be less convenient access than a cleanout wye. We might not be talking about the same thing. This is what I mean by a cleanout tee.


I was only considering the better angle to work with the wye has .

Also, does that T plug seal well enough? I don't believe the screw plug in the wye of my sewer line would.


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## BlackTiger

It's still a santee so if you invert it, it'll still guide the snake. And if we're talking about 3+" vents here, it's not going to be any trouble to send the snake whichever direction you choose. 

As for the plug, I silicone it for pressure testing. Best practice to silicon it each time but anecdotally I've seen cleanouts on the drain side hold water without silicone.


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## Ratchye

Thanks. We're moving forward with the installation of a "T" cleanout. With temps reaching a balmy -15 this week, I'm happy to have a plan, and will report back on how well it is working. 

We'll also be purchasing a few Frost Free Sewer Vents (https://frostfreesewervent.com/) and installing this summer when accessibility is less of an issue. Hopefully this two-pronged approach will eliminate future concerns.

Finally - I realize my initial post indicated our vent pipes were made of PVC. I should have edited it to say that they are made out of the black ABS material.

Thanks all for your continued interest in this topic.

Ratchye


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## Ghostmaker

Ratchye said:


> Yep - our pipe is 3". I hadn't thought about the spiderweb idea...hmmm....If anyone in colder climates has experienced these problems and has great ideas, please let me know!



Shouldn't your vent out the roof be 4 inch due to the colder temperatures of Alaska?


The real key to preventing excessive heat loss and freezing of the wet air inside your stack is better insulation. Insulating the exterior of these pipes, mainly as they progress through your frigid attic space, may prevent this excess heat loss. While there may currently be a thin layer of fibreglass or other pipe wrap material around these stacks, it may provide only minimal help. Covering the stacks with better-quality or thicker layers of insulation may be the only thing required to prevent freezing.
Adding more insulation around the bases, where the vents enter the attic, can also prevent quick cooling. If you succeed in this regard, the ice and blockage problems may disappear.

You might want to try this product to insulate your vent pipe http://www.armacell.us/products/aparmaflextubes/


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## Champagne

I installed a 24" vent stack kit from No Frost Venting last winter and it works great, easy to install .


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## TheyCalMeTriniy

Ratchye, how did the "Frost Free Sewer Vents" product work?


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## LaurieandPaul

This is the first winter we have not had to deal with frozen vent stacks because we purchased one 36" X 48" ELASTOMERIC INSULATION SHEET 1" WALL, cut it in half, wrapped each vent stack on the outside of the house from roof to top of stack, used some heavy-duty gorilla type tape to temporarily secure, then placed two adjustable stainless steel clamps (14" was too long, but that's what we bought, so that's what we used) to tighten down and keep the elastomeric foam in place. Wow, spent about $60, took a chance it would work, and it did! No heat tape, no more sewer smell coming in the house. This was one of the coldest Michigan winters we have had, so for this to keep ice from building up during the entire winter, this is a no-fail fix, easy, affordable and safe (provided your roof pitch isn't dangerously sloped). We did this before the weather got bad, late autumn. May not look overly attractive, but we don't care about that!


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## LaurieandPaul

This is the first winter we have not had to deal with frozen vent stacks because we purchased one 36" X 48" ELASTOMERIC INSULATION SHEET 1" WALL, cut it in half, wrapped each vent stack on the outside of the house from roof to top of stack, used some heavy-duty gorilla type tape to temporarily secure, then placed two adjustable stainless steel clamps (14" was too long, but that's what we bought, so that's what we used) to tighten down and keep the elastomeric foam in place. Wow, spent about $60, took a chance it would work, and it did! No heat tape, no more sewer smell coming in the house. This was one of the coldest Michigan winters we have had, so for this to keep ice from building up during the entire winter, this is a no-fail fix, easy, affordable and safe (provided your roof pitch isn't dangerously sloped). We did this before the weather got bad, late autumn. May not look overly attractive, but we don't care about that!


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