Shower or Bathtub Draining Slow? Causes, Fixes, and When It's a Bigger Problem

A shower that leaves you standing in ankle-deep water, or a tub that takes twenty minutes to empty, is the most common drain complaint we hear in Houston. Most of the time it is a plug of hair and soap scum a foot or two below the drain, and you can clear it yourself in half an hour. Some of the time it is the first sign of a branch line or main sewer problem, and clearing the tub will not touch it. This guide covers how to tell the difference, what to try first, and what to leave alone.

If the water is not draining at all, or more than one fixture is slow, skip to the section on bigger problems. The visit to find the cause is free; call or text (713) 409-7176.

Why Tub and Shower Drains Clog

Three things meet in a bathroom drain and bind together:

• Hair wraps around the stopper post and the crossbars at the drain opening, then collects everything that passes.
• Soap scum is what bar soap, body wash, and conditioner leave behind. It is sticky and coats the pipe wall.
• Mineral scale from Houston’s hard water hardens the soap scum into a crust. The same scale that fouls a water heater narrows the trap under your tub.

The result is a felt-like mat that forms in the P-trap and the first few feet of the branch line. A tub drain also has a second opening most people forget: the overflow, which joins the drain below the tub and is where a trip-lever plunger lives. Hair collects there too.

Older homes in the Heights, Oak Forest, Meyerland, and similar neighborhoods built before about 1980 often still have galvanized steel or cast iron drain lines. Those pipes rust from the inside, so the walls are rough and the opening is smaller than it was, which makes them clog sooner and harder. Our guide to cast iron pipes in older Houston homes explains what that looks like.

Which Stopper Do You Have?

You have to get the stopper out before anything else works. Take a photo first so it goes back the same way.

What to Try First

1. Clear the opening. With the stopper out, pull everything wrapped around the crossbars and post. Gloves help. In a trip-lever tub, the plunger you pull out of the overflow is often coated in hair; clean it before it goes back.
2. Use a plastic hair tool. The thin barbed strips sold at any hardware store reach 18 to 24 inches into the trap. Push it in, twist, pull slowly. Repeat until it comes out clean. This fixes most slow tubs by itself.
3. Hot water and dish soap. Squirt a generous amount of dish soap down the drain, follow it with a few quarts of hot (not boiling) water. Soap loosens the scum that holds the hair together. Boiling water can soften PVC joints and crack an older porcelain tub, so keep it to tap-hot.
4. Plunge with the overflow sealed. A plunger only works if it can build pressure. Stuff a wet rag into the overflow opening (or hold it with your hand) and plunge the drain with an inch or two of water in the tub. Ten firm strokes, then lift and check.
5. Run the water and watch. If it drains freely, put the stopper back and run hot water for a minute to flush what you loosened. If it is still slow, the mat is deeper than a hand tool reaches, and the next step is a cable.

What Not to Do

• Chemical drain cleaners. They work poorly on hair, sit in the trap as a caustic pool, heat up enough to damage PVC joints, and eat at older galvanized and cast iron. They also make the drain hazardous for whoever cables it next. Our guide on whether Drano is safe for your pipes goes deeper.
• Wire coat hangers. They scratch the finish on the drain, gouge the inside of the pipe so scum sticks faster, and can get stuck in the trap.
• Mixing products. Baking soda and vinegar is harmless but mostly useless on a real clog. Mixing a chemical cleaner with anything else, including a second brand, can produce heat or fumes.
• Forcing a stuck stopper. A stopper that will not unscrew is usually scaled in place. Penetrating oil, a cloth-wrapped pair of pliers, and patience beat a wrench that snaps the post.

When a Slow Tub Is a Bigger Problem

A single slow tub with everything else draining normally is a local clog. These signs mean the problem is further down the line and clearing the tub will not fix it:

• Other fixtures are slow too. A slow tub plus a slow bathroom sink means the branch line they share is clogged. A slow tub plus a slow kitchen sink on the other side of the house points at the main line.
• Gurgling. The tub drain or the toilet gurgles when another fixture drains. That is air being pulled through a trap because the line past it is restricted. Our guide on why the toilet gurgles when the shower or washer drains covers that pattern.
• Water rises in the tub when the toilet flushes. The toilet’s water has nowhere to go and backs into the lowest drain in the house, which is usually a tub or shower. That is a main line blockage.
• It keeps coming back. A tub that clogs every few months after being cabled has something the cable is not fixing: a belly in the line, a root intrusion, or a pipe that has rusted rough. Read the sewer line warning signs if that sounds familiar.
• Sewer smell at the drain. A trap that drains slowly can also dry or siphon, letting sewer gas through.

In Houston’s clay soil, main lines shift and sag as the ground swells and shrinks through the year, so a drain that was fine for a decade can start backing up after one dry summer. That is a line problem, not a hair problem.

Cabling vs. Hydro Jetting

When hand tools fail, a plumber has two ways to clear the line.

A drain cable (snake) is a steel coil with a cutting head that breaks through the clog and pulls hair out. It is the right tool for a tub or shower branch: fast, effective on hair, and gentle on older pipe. It goes in through the overflow on a tub, or through the drain on a shower, or through a cleanout if there is one.

Hydro jetting uses high-pressure water to scour the pipe wall clean along its full length. It is the right tool when the line is coated in grease and scale, when a cable keeps punching a hole that closes up again, or for main lines with years of buildup. It is not usually needed for a single tub. The hydro jetting vs. snaking guide lays out when each one makes sense, and the drain cleaning cost guide covers the Houston market ranges for each.

For pre-1980 cast iron, a camera look after cleaning is worth it. If the inside of the pipe is rough and flaking, no amount of cleaning makes it drain like new, and you want to know that before you pay to clear it a fourth time.

Keeping It Draining

• A hair catcher at the drain opening stops the mat from forming. The silicone or stainless ones that sit in the opening cost a few dollars and get emptied once a week.
• A monthly hot flush. Run the hot tap for two or three minutes into an empty tub. It softens soap scum before it hardens into scale.
• Rinse conditioner and oils. The thicker the product, the faster the scum forms. Rinsing with the water running a bit longer helps.
• Pull the stopper twice a year and clear the post, even if nothing feels slow yet.

When to Call

Call Hugo Plumbing when:

• Hand tools and a plunger have not fixed it, or the tub will not drain at all.
• More than one fixture is slow, or anything gurgles.
• Water comes up in the tub when the toilet flushes. That one is urgent, since the next flush can put sewage on the floor.
• The drain has been cleared before and clogs again within months.
• The home has cast iron or galvanized drains and you have never had a camera look.

Drain cleaning is priced on site, because the right price depends on which drain it is, how we get into it, and what the cable finds. The diagnosis visit is free, with no trip charge or diagnostic fee, and every job gets a flat written price before work starts. Licensed master plumbers (MPL 41319) are available 24/7 at (713) 409-7176.

Frequently Asked Questions

Why does my shower drain slowly even though I just cleaned it?

The clog is usually below where a hair tool reaches. Hair, soap scum, and the mineral scale Houston hard water leaves behind build up in the trap and the branch line a few feet past the drain opening. Pulling what is in the top few inches helps for a week; the rest of the mat is still there. A cable run through the overflow or the drain clears the full length of the trap arm.

Is it safe to use Drano or a liquid drain cleaner in a tub?

We do not recommend it. Tub and shower clogs are hair and soap, which chemical cleaners dissolve poorly, and the liquid then sits in the trap as a caustic pool. It damages older galvanized and cast iron drains, can crack PVC joints when the reaction heats up, and makes the job unsafe for whoever cables the line next. A plastic hair tool, hot water and dish soap, and a plunger with the overflow sealed are the safer first moves.

How do I get the stopper out of my bathtub drain?

It depends on the type. A lift-and-turn or push-pull stopper unscrews from the center post or the body with a counterclockwise turn. A pop-up stopper lifts straight out, often with a rocker arm attached, and the lever in the overflow plate comes out once you remove its two screws. A trip-lever drain has no stopper in the opening; its plunger is inside the overflow tube and comes out with the overflow plate. Take a photo before you start so it goes back the same way.

My tub backs up when I flush the toilet. Is that the same clog?

No. A tub that fills with water when the toilet flushes means the blockage is past the point where the tub and toilet lines join, which is the main sewer line or the branch feeding it. Clearing the tub drain will not fix it. That pattern calls for cabling or jetting the main line, and in an older Houston home it is worth a camera look to see why it keeps happening.

How much does it cost to have a plumber unclog a shower or tub drain in Houston?

Hugo Plumbing prices drain cleaning on site because the number depends on which drain, how it is accessed, and what the cable finds. The diagnosis visit is free, with no trip charge, and you get a flat written price before any work starts. For context, our drain cleaning cost guide walks through the typical Houston market ranges for a single fixture versus a main line.

If your tub won’t drain, call Hugo.