Walk the perimeter of the building, and scan the bottom third of the exterior wall for protruding drainpipes. Pay particular attention to walls that border plumbed rooms, such as bathrooms, kitchens and laundry rooms. If weeds or plants block your view, trim or prune your landscaping with a weed trimmer or shears to clear obstructions from the wall. Search for black pipes. Most residential drainpipes are plastic ABS or cast iron; both types are black.
Inspect drainpipes that protrude from the building's exterior wall. Pipes that protrude outward are typically cleanouts, and pipes that climb the wall and extend through the roof are usually vent pipes. Inspect the pipes that protrude away from the wall for screw-on caps or screw-in plugs. Pipes with caps or plugs are cleanouts.
Search the building's exterior walls for access doors or metal access plates. Open or loosen doors or plates. Shine a flashlight into the access opening, and inspect the building's crawlspace for pipes. Inspect the pipes for cleanout caps.
Attach a pipe wrench to the cleanout cap or the cleanout plug's knob. Twist the cap or plug counterclockwise to loosen and remove the cap from the cleanout.
Things You Will Need
- Weed trimmer
- Hedge shears or lopping shears
- Pipe wrench
- Old cleanout caps and plugs are notoriously difficult to loosen; if you have trouble opening a cleanout, apply a grease-free, penetrating lubricant to the cap or plug.
- Cleanout openings are the ideal place to use drain augers; if you face a particularly stubborn clog, consider renting a power auger from your local home improvement store.