How to Clean and Unclog a Plumbing Vent

Conroy Baltimore
Written by Conroy Baltimore
Updated May 11, 2022
Mother and child washing hands in kitchen
Photo: E+ / Getty Images
Difficulty

Intermediate

Perfect for handy homeowners.

Time to complete

3 hours

1 to 3 hours, depending on the size of the blockage.

Cost

$30 to $50

$30 to $50

Unclogging plumbing vents is maintenance you never knew your home needed

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What you'll need:

TOOLS

  • Ladder
  • Garden hose
  • Plumbing auger (snake)
  • Screwdriver
  • Rope
  • Hammer
  • Hacksaw
  • Mask
  • Gloves

SUPPLIES

  • Nails
  • Stakes
  • PVC coupling
  • Plumber’s cement

Do you hear a loud gurgling noise from your sink? What about your home air quality—have you noticed unpleasant odors? If so, you might have a plumbing issue on your hands, but not one of the usual ones. It’s likely a clog in your plumbing vent.

Your plumbing vent stacks allow air into your plumbing system to keep the water pressure in your pipes at a reasonable level and keep sewer gasses at bay. But over time, they can get clogged, and those sewer gasses will enter your home, posing health risks to you and your family. You’ll also have backed-up plumbing issues that will need your immediate attention.

To avoid those problems altogether, here’s how to clean and unclog your plumbing vents.

  1. To the Roof, We Go

    An excellent method for cleaning your plumbing vent involves climbing on your roof. However, remember that working on a roof is extremely dangerous and is an advanced-level DIY—you shouldn’t try this unless you know what you’re doing up there. Be sure to call a pro if you need help with this part of the job. 

    Before starting, make sure your ladder has non-slip feet and is on a firm, stable surface. Secure it at the base by tying it to a sturdy structure with rope. If there’s nothing to support it, you can use a stake and tie the rope to that.

    You’ll also want to ensure the top is secure because the ladder can slip to the side as you start climbing. To prevent this from happening, equip a stabilizer to keep the ladder in place. Stabilizers have wide metal arms with non-slippery pads that attach to the house wall. You’re still up high, but there’s more peace of mind since you know the ladder isn’t going anywhere.

  2. Clearing the Obstructions

    Next is clearing the blockage. Locate your plumbing vent, which is the large pipe that’s sticking out of your roof (not the chimney, if you have one). If you have multiple pipes on your roof, place your ear near the openings and have someone flush the toilet. The pipes will amplify the flushing, making it easier to locate the correct vent.

    Depending on your system, the plumbing vents might have a cap, which you can remove with a screwdriver. Once it’s opened, inspect the vent pipe for any visible obstructions, such as branches, leaves, and sports balls, and remove them if possible. 

    Don’t be alarmed if you find the remains of rodents or birds who can get trapped and cause a clogged plumbing vent. If you happen to see one, it would be best to remove it. Hopefully, you have a garbage bag with you—if not, you’ll need to climb back down the ladder. 

    After retrieving a bag, put on a pair of gloves and reach down into the vent to grab the carcass. Make sure you wear a mask, too, because the smell might be repulsive. Then put the animal in a waste bag so you can dispose of it properly.

    After removing the visible blockages, use your plumber’s auger (also known as a snake) to unclog anything that’s further down your pipes. The auger can help loosen up years of gathered debris. Sometimes that can do the trick, but if not, it’s on to the next step.

  3. Spray Your Cares Away

    If you still feel more obstructions in your plumbing vent after using the auger, it’s time to break out the heavy artillery—also known as your garden hose. Adjust the nozzle to its most powerful setting and spray water down the pipe.

    Spraying the hose will help remove any remaining debris in your vents and potentially get your plumbing system back on track. Continue spraying water into the pipes to push everything down your sewer line.

  4. Check Your Work

    Plumbing vent on roof
    Photo: iStock / Getty Images

    You aren't done yet after clearing out the debris; you have to check your work. Have someone flush the toilet while holding your hand over the vent to feel for suction. 

    If you’re still having issues after completing these steps, contact a local plumber to come and assess your plumbing vents. Not only will they fix your system, but they can also provide preventative plumbing maintenance tips to keep the issue from happening again.

Unclogging Plumbing Vents From Inside Your Home

For those who aren’t fond of ladders, you’re in luck. Unclogging plumbing vents from inside your home is possible, but the steps are slightly different. This method will only be helpful if your vent pipes are PVC and not cast iron.

  1. Your first step includes taking a (hopefully) short stroll up to your attic and locating the vents above your kitchen or bathroom. 

  2. Cut away a portion of your PVC piping using a hacksaw, so you have access to the clog.

  3. Grab the snake and maneuver through the piping until you find the blockage. It could be above or below you, so run the snake in that direction until you clear it. 

Replacing PVC piping costs $0.50 to $1 per linear foot. To repair the gap, use a PVC coupling with plumber’s cement to bridge the pieces together. You’ve successfully unclogged your plumbing vent and restored your system to its standard functionality.

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