Sluggish drains aren’t always caused by obstructions in the drain lines. Although it might seem counterintuitive, you often can fix them by climbing to the roof, because that’s where the vent openings are located. When the vents get blocked, air can’t get into the drains, and the vacuum produced by rushing water can slow it down or stop it altogether. Even worse, the vacuum can pull water out of drain P-traps and toilet bowls and allow sewer gases into your house. None of this needs to happen, though, because cleaning the vents is a routine maintenance task.
Set up a ladder so you can climb on the roof. Be sure the feet of the ladder are firmly planted on level ground and the top extends 3 feet above the roof line. Brace the ladder by securing the lower portion with a rope to prevent the feet from sliding away. Tie the rope to a porch column or an eye hook screwed into the foundation. Screw an eye hook into the fascia and secure the top of the ladder by tying it to the hook with a second rope.
Bring a screwdriver and a garden hose with an adjustable nozzle with you when you climb onto the roof. If the vent has a cap, you’ll need the screwdriver to unscrew it. The purpose of the garden hose is to spray water into the vent. In most cases, that’s all you’ll need to do to clear it.
Inspect the vent opening for obstructions. Sometimes leaves and debris can collect there, and you can restore air circulation by clearing obstacles.
Set the nozzle to “jet” or “full” and spray directly into the vent opening if there aren’t any visible obstructions. The water will probably clear debris that collected inside the line. If there is a large blockage, such as years of debris or even an animal or bird that crawled into the vents and died there, water might fill the pipe and back out of the opening. In this case, you’ll need a more aggressive method to remove the blockage.
Leave the hose on the roof while you climb down and fetch a 10- to 20-foot plumbing auger, also known as a snake. Insert the head into the vent opening and feed in the cable until you encounter the blockage. Crank the handle to work the head through it. When you are successful, water will begin to drain. At this point, retract the auger. The debris will probably come with it.
Spray water into the vent opening until you are sure it won’t back up again.
Things You Will Need
- Eye hooks
- Garden hose
- Adjustable nozzle
- Plumbing auger
- If you find debris in the vent opening, prevent it from collecting in the future by fitting the opening with a cap.
- Wear rubber-soled shoes for traction when climbing on the roof. If your roof has a steep pitch that prevents walking on it safely, hire a professional to clear the vents.