Drains, sewer lines and basement backups

What causes most clogs and slow drains

A drain is a sloped pipe that relies on gravity. Anything that narrows it or catches debris slows the flow, and once flow slows, more debris settles. That is why a drain that has been a little sluggish for months can stop completely in one evening.

Most household clogs start close to the fixture: hair and soap in a tub drain, food and grease in a kitchen sink, too much paper in a toilet. If one fixture is slow and everything else drains normally, the problem is usually in that fixture's trap or branch line.

When several fixtures act up at once, especially the lowest ones in the house, the trouble is further down. A basement floor drain that backs up when the washer empties, or a toilet that gurgles when you run the tub, points to a blockage in the main drain or the sewer lateral that carries everything to the street.

The Miami Valley's hard water adds to the problem. Minerals combine with soap and grease to form scale inside pipes. In many older Dayton-area homes, the original cast iron drain lines are also rough and corroded inside, which catches debris that smooth plastic pipe would let pass.

Grease, wipes and hair

Cooking grease goes down the sink as a liquid and turns solid a few feet later as it cools. It coats the pipe walls, traps food particles and slowly closes the line. Running hot water while you pour only moves the problem further along. Let grease cool in a can or jar, put it in the trash, and scrape plates before rinsing.

Wipes are the other big one. Many are labeled flushable, but they do not break down the way toilet paper does. They snag on rough spots, roots and joints, then tangle with grease into mats that can block a main line. The safest rule is that only toilet paper goes in the toilet.

In bathrooms, hair binds with soap. A basic strainer over the tub and shower drain catches most of it. Coffee grounds, eggshells, rice and pasta should stay out of the disposal, because they settle in low spots and build up.

For more on everyday clogs, and why chemical cleaners often cause more trouble than they solve, see why drains keep clogging.

Tree roots and older clay sewer laterals

The sewer lateral is the pipe that runs from your house to the public sewer main. In many older neighborhoods around Dayton, laterals are clay tile laid in short sections, or cast iron. Clay pipe itself holds up well, but the joints between sections can crack and shift after decades of freezing, thawing and settling in the region's heavy clay soils.

Tree roots go looking for water and nutrients, and a leaking sewer line offers both. A hairline gap at a joint is enough for a fine root to get in. Inside the pipe it grows into a dense mass that catches paper and grease. Willows and silver maples are well known for it, but almost any tree near the line can cause trouble.

Common signs include slow drains throughout the house, gurgling toilets, a backup at the basement floor drain, and problems that come and go. A line can seem fine for a while after it is cleared, then slow down again as the roots grow back.

In many communities the homeowner is responsible for the lateral, sometimes all the way to the main. Check with your city or sewer district so you know where your part ends. See tree roots in sewer lines for signs and repair options.

What a sewer camera inspection shows

A camera inspection takes the guessing out of sewer problems. A plumber feeds a waterproof camera on a flexible cable through a cleanout and watches the pipe on a screen as it travels toward the street. The camera shows roots at joints, cracks, offset sections, low spots where water sits, grease buildup and collapsed pipe. Most systems include a locator, so the plumber can mark on the ground where a problem sits and roughly how deep it is.

An inspection makes sense when you have repeat backups, after roots have been cut out of a line, before you replace a driveway or plant trees over the sewer, and when you are buying an older home. A recording of the line gives you something concrete to compare repair options against, and a baseline for later inspections.

If the line is fully blocked, it usually has to be cleared before the camera can get through.

Sump pumps and spring storms

Many Miami Valley basements have a sump pit, a basin that collects groundwater from drain tile around the foundation. When the water rises, a float switch turns the pump on, and it pushes the water out through a discharge pipe away from the house. In spring, when heavy rain falls on ground that is already saturated or still partly frozen, a sump pump can run for hours.

A sump pump handles groundwater, not sewage. A sewer backup comes up through floor drains and low fixtures. A sump failure usually shows up as water seeping in along the walls or floor, or overflowing the pit. Both can happen in the same storm, so it helps to know which is which.

Test the pump before the wet season. A battery backup keeps pumping when a storm knocks out power, which is often when you need it most. Most communities do not allow sump pumps to discharge into the sanitary sewer, because that extra clear water overloads the system during storms. See sump pump basics for testing steps and winter tips.

How to prevent basement backups

A few habits and the right equipment go a long way:

• Keep grease, wipes and food scraps out of drains.
• Find your main cleanout and keep it accessible, so a plumber can reach the line quickly.
• Have the lateral inspected if you have had root problems, or if you live in an older home with large trees near the sewer.
• Test your sump pump each spring and fall, and keep the discharge line clear and pointed away from the foundation.
• Clean gutters and extend downspouts so roof water does not soak the soil next to the basement walls.
• Ask a plumber about a backwater valve if your floor drain has backed up during storms. It lets wastewater flow out but closes if water tries to flow back in from the main. Installation often requires a permit, so check with your city.
• During a heavy storm, hold off on laundry and long showers if your street is prone to sewer backups.

When to call a plumber

A plunger or a cleaned-out trap will fix many single-fixture clogs. Call a plumber when more than one fixture is slow or backing up, when sewage comes up through a floor drain, when a clog keeps returning, when you smell sewer gas indoors, or when your sump pump runs nonstop, will not turn on or lets the pit overflow.

Stay out of standing water in a basement if it could be touching outlets, appliances or extension cords. Treat any sewage backup as contaminated, and keep children and pets away. Do not pour chemical cleaner into a fully blocked line, because whoever opens it next can be splashed with it. When in doubt, reach out to a plumber and describe what you are seeing.

Frequently asked questions

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