How to Unclog a Vent Pipe on Your Roof

If you’ve got a horrible clog that is located deep in your pipes, you might need to know how to unclog a vent pipe on your roof.

Why?  Because some clogs have either worked their way passed the P trap or the clog started in the T or 90 degree joints much deeper in your pipes.

Find out when and how you unclog the vents on your roof to get your pipes running clear.

how to unclog vent pipe on roof
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How Do I Know if my Plumbing Vent is Clogged: Clogged Vent Pipe Symptoms

So you’ve worked your butt off with a drain auger or a toilet auger to conquer your clog, but you’ve STILL got issues with how your pipes are draining.  Most clogs are at or before the P Trap.  But sometimes, you’ve got a clog that’s much deeper.   

Clogs can also form at the 90 degree or T joint in your pipes where the pipe from your sink, drain or toilet joins your main sewer line inside your walls.  This long pipe is called a plumbing vent, sewer vent, plumbing stack vent, or roof vent.   

A plumbing vent lets air into your pipes to help regulate air pressure and make sure that waste is moving through your pipes properly.  They also work to vent any sewer gases and nasty odors.  If your pipes are starving for air, they can’t remove waste water and fumes. 

How to Tell if Your Plumbing Vent is Clogged

What happens if a vent pipe is clogged?  Plumbing stack vent problems can be identified a few different ways.   Here are the 4 ways that we go about determining if we’ve got a clogged vent pipe.

First, if you’ve worked your butt off and can’t clear the clog by using augers, chances are the clog is deeper than your auger can reach going through your drain.   

Second, if you’re having venting problems with your toilet or drains they are probably draining very slowly.   

Third, if your plumbing is making gurgling sounds in the pipes, that’s trapped air trying to escape through the clog in the vent. 

Fourth, if your vent pipes clogged, you might smell nasty sewer gas.  That’s because the vent pipes work to remove and block those smells from coming into your home. 

How to Unclog a Vent Pipe on Your Roof: DIY Steps 

Follow the steps below to clear your plumbing vent stack of any clogs and build ups.  Get those drains and pipes running like new. 

Really, you should be running a drain auger in your vent as a part of routine home maintenance.  Set up a schedule and stick to it.   

Part of routine maintenance would be clearing any debris from in and around the pipe.  You should place a protective cap on top of your vent that still allows all the air to flow, to keep birds and other animals or debris from getting inside. 

Tools Needed to Unclog a Vent Pipe 

  • Screwdriver 
  • Gloves 
  • Work Clothes 
  • Drain Auger 
  • Ladder 
  • Flashlight 

Steps to Unclog a Drain from the Roof 

Put on some work clothes and safety goggles, you don’t want that nasty stuff in your face, clothes or eyes. 

  1. Get yourself up on your roof using a ladder that is properly secured 
  2. Remove the Vent Pipe Cap (if required) 
  3. Inspect the inside of the vent pipe with a bright flashlight 
  4. Grab the debris if you can see it and test your pipes 
  5. If you can’t see the clog, grab your drain auger 
  6. Feed your auger down the pipe 
  7. When you feel the auger cable stop, you’ve hit your clog 
  8. Start twisting your auger cable around to grab hold of the clog and any other gunk that is in the vent pipe 
  9. Wind your auger cable back out of your vent 
  10. Test your drains, if they run fine, you’re finished! 

If not, insert you auger cable back down the vent pipe and work it until your drains run clear. 

Some folks will use a garden hose to clear their vent pipe.   That’s a short-term solution.  There is still gunk gathering on the sides of your pipe that you need to clear out.  If you only use a garden hose, you’ll be back up on your roof in no time clearing another vent pipe problem. 

Can a Clogged Vent Cause a Toilet to Overflow? 

Vents allow the air displaced by flushing water down your toilet to escape out your rooftop.  If the air has no place to go, and the vent is clogged, your toilet could overflow because the toilet can’t flush properly.  Same story for your drains. 

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Can I Pour Drain Cleaner Down my Vent Pipes? 

If you don’t have a proper drain auger, you might look towards another easier solution.  Can you put drain cleaner in a vent pipe? Any plumber will tell you, avoid drain cleaner like Drano at all costs.  They do offer a short-term solution if you don’t have a drain auger handy.   

But, your vent will plug up again real soon, because a drain cleaner can’t do a good job of removing all the gunk that’s gathered at the T junction of your vent and your pipe from your drain/toilet.   

Pipes on Your Roof: Sewer Vent Pipe Location 

You’ll usually find a vent pipe on your roof.  Sometimes it might be in your yard.  Just take a look at your roof from a distance and you will see a long straight pipe more than a foot long sticking out of your roof.   

How much Does it Cost to Unclog a Vent Pipe? 

The cost to snake a roof vent can be pretty steep.  You’re paying a pro to come buy with all their tools and climb on your roof.  Depending on your clog, it could cost $100’s of dollars to get that vent stack cleared.  Take it from us, get yourself a drain auger and maintain your vent pipe on a routine basis to avoid this sort of expense. 


How to unclog a vent pipe on your roof is a DIY job so if you’ve got a drain auger, you don’t need to call in a Pro.  Save your cash and auger that vent pipe on your roof yourself.