How to Find Your Sewer Cleanout (and What to Do If You Don't Have One)

What a cleanout is and why it matters

Every drain in your house joins a single main line that leaves the building and runs to either the public sewer or a septic tank. A cleanout is a fitting on that line with a removable cap. Pull the cap and you are looking straight into the pipe. That is where a sectional drain machine, a hydro jetter or a push camera goes in.

Without one, the options are worse. We can pull a toilet, which means a new wax ring and a messy floor. We can run a cable down a roof vent, which means a ladder on a wet roof in November and a cable fighting its way around two bends before it even reaches the main. Both work, but neither is as fast, as clean, or as effective as a straight shot through a cleanout. When the camera goes in, the difference is even bigger; a camera through a toilet flange rarely gets as far as one through a proper cleanout.

What it looks like

Outside, a cleanout is a round cap, typically three or four inches in diameter, flush with or slightly above the ground. On homes from the last forty years it is usually white PVC or black ABS with a square nut molded into the center of the cap. Some are covered by a green or black plastic lid about the size of a dinner plate, similar to an irrigation valve box. Older installations may be a brass or cast iron cap on a clay or cast iron riser.

Inside, cleanouts show up as the same style cap on a fitting in the crawlspace, usually where the main line makes its turn to exit the foundation. Basements, which are rare in Kitsap but common in parts of Tacoma, often have a cap in the floor near the foundation wall or a riser coming up out of the slab. You may also find small cleanout caps on walls behind toilets or in the back of a cabinet under a sink; those serve a branch line, not the main, and they help with that one fixture only.

Where to look on your property

Figure out which direction your sewer goes. On sewer, that is toward the street where the main runs, or toward an easement at the back or side of the lot in some older Bremerton and Port Orchard neighborhoods. On septic, it is toward the tank, which is often in the front or side yard with the drainfield beyond it. The cleanout is almost always within a few feet of the foundation on that side, often lined up with a bathroom or the kitchen.

Walk the foundation slowly and look for anything round. Bark mulch, decades of sod, a raised flower bed, a deck built over the spot, or a gravel driveway that was widened can all bury a cleanout. We find a lot of them under the edge of a deck in Gig Harbor and Silverdale homes where the deck went in after the house. A long screwdriver pushed into bark along the foundation will hit a cap with a distinct click.

If the yard turns up nothing, check the crawlspace near the exit point of the main line, and look at the roof for the largest vent pipe, which usually sits above the main bathroom. The main line typically leaves the house roughly below that vent.

Why so many local homes do not have one

Plumbing codes have required accessible cleanouts for a long time, but the specifics on exterior cleanouts near the building have changed over the decades, and enforcement on remodels was loose. A lot of the housing stock near PSNS and along Sinclair Inlet went up fast in the 1940s through 1970s for shipyard families, and plenty of those homes have a main drain that goes from the crawlspace straight into the ground with no access at all. Cabins in Mason County and older waterfront places on Hood Canal and Fox Island are the same story, sometimes worse.

Add to that the homes where a cleanout existed but was paved over, buried under a slab for an addition, or cut off when a septic system was converted to sewer along Beach Drive or in Manchester. The pipe is there. The access is gone.

When we camera one of these lines and find a problem, we recommend adding a cleanout at the same time as any repair. Once the ground is open, putting a two-way cleanout on the line is a small addition to the job, and it changes every future service call from a project into a quick visit.

Using the cleanout during a backup

If sewage is coming up in a tub or floor drain and you have an exterior cleanout, you can give the line somewhere else to go. Put on gloves, kneel to the side rather than directly over the cap, and loosen it slowly with a wrench on the square nut. If the line is full, you will hear it and see water seeping at the threads. Let it ease out before you take the cap off completely. The line relieves into the yard, which is ugly but a lot better than into the hallway.

Do not do this with an interior cleanout in a crawlspace or basement unless you want sewage there instead. And do not put chemicals down a cleanout; whoever opens the line next, probably us, ends up wearing them.

After the backup is cleared and the cap is back on, snug it by hand plus a quarter turn with the wrench. Overtightened caps crack, and a cap that is cracked lets rainwater and roots into the line.

Cleanouts on septic systems

Septic homes have a few more pieces. The house cleanout sits near the foundation as described. The septic tank has one or two lids, often green plastic risers or buried concrete lids, and those are for pumping and inspection, not for drain cleaning. Beyond the tank there may be a distribution box and a pump chamber with its own lid and an alarm box on the house.

A slow drain on a septic system can be a clogged house line, a full tank, a failed effluent pump, or a saturated drainfield in the wet months, and each one is a different call. We handle the house line, the cleanout and the pump chamber. Tank pumping and drainfield work belong to a septic company. When you call, tell Corinne when the tank was last pumped; it saves everyone a wasted trip.

How we add a cleanout

We locate the main line with the camera and a locator, then dig down to it just outside the foundation. On most properties around here that is two to four feet of glacial till, sometimes with a layer of clay that holds water in winter, so the hole stays open and the work goes quickly. We cut in a two-way cleanout fitting, bring a riser up to grade, cap it, and backfill. On a sewer line repair, the cleanout goes in at the point of repair and sometimes at the property line as well.

A two-way fitting is worth asking for. It lets equipment run toward the street or the tank to clear a clog, and back toward the house to clear the line under the slab or crawlspace. We always leave the cap visible, and we will show you where it is before we pull out of the driveway.

• Keep bark and sod from burying it; a marker stake or a paver around it helps
• Do not build a deck, shed or patio over it without a hatch
• Check that the cap is snug after any landscaping work
• Photograph its location and keep the picture with your house documents