Every plumber asks the same first question on a main-line backup: where is your cleanout? Most homeowners have never looked. Some find it in two minutes once they know what they are looking for; some discover their 1962 house never had one, which is why the last plumber pulled a toilet to clear the line. This guide shows you where to look, what you are looking for, and what to do if it is not there.
A sewer cleanout is a capped pipe, usually 3 or 4 inches across, that gives direct access to your main sewer line. In Houston it is most often found outside, near the foundation on the side of the house with the bathrooms, or near the property line by the street. Look for a round plastic or metal cap at ground level, sometimes inside a small round box. Many homes built before the 1970s have none; if yours does not, having one installed turns every future drain backup from a project into a short visit.
- The cleanout is the access point for cabling, jetting and camera-inspecting the main line.
- Look near the foundation below the bathrooms, along the line to the street, and at the property line.
- Older Houston homes often have no exterior cleanout at all, only a roof vent or a pulled toilet.
- No cleanout means every main-line job costs more and takes longer.
- A two-way cleanout at the property line also lets a plumber prove when the problem is on the city's side.
What a cleanout looks like
A short vertical pipe rising to ground level with a threaded cap, usually white, black or green PVC on newer homes, or a cast iron plug with a square nut on older ones. The cap may sit flush with the lawn, stick up an inch or two, or be inside a round plastic or concrete box with a lid, the same kind that covers irrigation valves. In a newer subdivision there are often two, one at the house and one at the property line. Inside a garage or utility room it can be a capped pipe coming out of the wall or floor near the water heater.
A two-way cleanout has a double fitting, sometimes two caps side by side, which lets equipment go toward the house or toward the street from the same spot.
The five places to look
- Along the foundation on the bathroom side of the house. The main drain leaves the house near where the bathrooms are. Walk the foundation on that side and look at ground level for a cap, often a few feet out from the wall.
- In a straight line from there to the street. The sewer lateral runs from the house to the city main under the street. A second cleanout, if there is one, sits on that line, usually within a few feet of the sidewalk or property line.
- Inside a valve box. Look for round green or black lids in the lawn or flower beds along that line. Open them; one may be a cleanout rather than an irrigation valve.
- In the garage, utility room or a closet on the plumbing wall, especially in townhomes and in homes where the laundry is on an exterior wall.
- Under landscaping. Mulch, a bed of ground cover or a layer of sod added since the house was built can bury a cleanout completely. Probe gently with a screwdriver along the foundation if the first four places turn up nothing.
If the house was built after the early 1980s, keep looking; it almost certainly has one. If it was built before 1970, it may not.
Why older Houston homes have none
Exterior cleanouts became standard in plumbing codes over the 1970s. Before that, builders often provided access only through roof vents and the toilet flanges. Thousands of homes in Meyerland, Bellaire, Sharpstown, Oak Forest, the Heights and the older parts of Spring Branch and Westbury still have no exterior cleanout. The main line under those houses is also the most likely to be cast iron or clay, which means it needs the most cleaning, from the worst access.
What it costs you to have no cleanout
Without a cleanout, a plumber clears the main line from the roof vent, which is slow and limited by the cable's reach, or by pulling a toilet, which adds an hour, a new wax ring and the risk of breaking an old flange. A camera inspection has the same problem. Every job on the main line carries that overhead, every time. Homeowners with recurring root problems pay it once or twice a year.
Installing a cleanout is a one-visit job: locate the line, dig to it, cut in a fitting, run a riser to grade with a cap, camera the line while it is open, and backfill. After that, clearing the line is a short, cheap visit from the yard.
Once you find it: three things to do
- Photograph it and note where it is, with a landmark. Add it to the house file. The next person to need it will be someone standing in sewage at night.
- Check that the cap comes off. Caps that have never been removed seize. If it will not turn by hand or with a wrench, do not force a plastic one; a plumber can replace a seized cap in minutes. Never open a cleanout when the drains are backed up; it is under pressure and it will empty onto your shoes.
- Keep it clear. Do not build a deck, pour a patio or plant a shrub over it. If landscaping has to cover it, use a valve box with a lid.
One-way or two-way
A standard cleanout at the house sends equipment toward the street. A two-way cleanout, usually at the property line, lets a plumber go toward the house or toward the city main. That matters when the city's main is blocked and the house backs up through no fault of its own: a camera sent toward the street from a two-way cleanout shows the blockage past the property line, which is what the City of Houston needs to see before it sends a crew. If a cleanout is being installed from scratch, a two-way at the property line is worth the small extra cost.
The signs you are about to need it
Gurgling from a toilet when the tub drains, the lowest drain in the house filling with water, every fixture slow at once, or a sewer smell in the yard after rain. Those are main-line symptoms. If you know where the cleanout is, the call to the plumber is short and the visit is shorter.
Frequently asked questions
What does a sewer cleanout look like?
A round pipe, 3 to 4 inches across, rising to ground level with a threaded cap, often white or black PVC, sometimes cast iron with a square nut. It may sit inside a small round valve box in the lawn.
Where is the sewer cleanout usually located?
Near the foundation on the side of the house with the bathrooms, and sometimes a second one near the property line by the street. In some homes it is in the garage or a utility closet.
Does every house have a sewer cleanout?
No. Many Houston homes built before the 1970s have no exterior cleanout, only roof vents and the toilet flanges. Codes since then require them.
Can I open the cleanout myself?
If the drains are flowing, yes; unscrew the cap to check it is not seized, then replace it. Never open it when the line is backed up: it is under pressure and sewage will come out.
What does it cost to add a cleanout?
It depends on how deep the line is and what is on top of it (grass, concrete, a deck), so it is quoted after the line is located, and before any digging. It is a single-visit job for most homes.
What is a two-way cleanout?
A cleanout with a double fitting that lets a plumber send a cable, jetter or camera toward the house or toward the street from the same opening. Installed at the property line, it also shows whether a blockage is on the city's side.
