Why does my drain keep backing up even after I snake it?

If a drain backs up again within days or weeks of being snaked, the snake likely punched through a soft clog without fully clearing it, or the underlying issue is not a simple clog — it could be grease buildup coating the pipe walls, tree root intrusion, a crushed or sagging pipe section, or a partial obstruction deeper in the line. A camera inspection is the best next step.

What causes drains to back up repeatedly?

Recurring backups are usually caused by one of four things: grease buildup that coats the inside of the pipe over years, tree roots that have grown into the sewer line through cracks, a pipe that has sagged or bellied and holds standing water, or a slow partial blockage that builds back up faster than normal.

Is it safe to use chemical drain cleaners for a backup?

Chemical drain cleaners can dissolve some organic clogs, but they have real downsides: they are highly caustic and can damage older metal pipes and PVC joints with repeated use, they do not work on solid obstructions or root intrusions, and they can be hazardous if mixed or splashed. For occasional slow drains they may provide temporary relief; for a drain that keeps backing up, they are not a solution.

Multiple drains are backing up at once — what does that mean?

When more than one fixture backs up simultaneously — for example your toilet and your shower both drain slowly at the same time — that points to a blockage in the main sewer line rather than a branch line. This is a more urgent situation because the entire drainfield of your home is affected. Call a plumber promptly.

How much does drain cleaning cost in Pflugerville?

Standard drain snaking runs $100 to $250 for a single drain. Hydro-jetting — which scours pipe walls with high-pressure water — typically runs $300 to $600. Alberto Plumbing offers $20 off drain cleaning and provides upfront pricing before starting. Call (512) 429-6933.

Can tree roots really grow into my sewer line?

Yes, and it is more common than most homeowners expect. Tree and shrub roots naturally seek out moisture and can infiltrate clay or older cast-iron sewer pipes through existing cracks or joints. Once inside, they grow rapidly and can completely block the line. Root intrusion almost always requires professional equipment to clear and address.

Drain Keeps Backing Up: Causes and When to Call a Plumber

Is It One Drain or Multiple Drains?

This question changes everything about how you approach the problem.

One slow or backed-up drain: The clog is almost certainly in the branch line — the section of pipe serving just that fixture. This is usually a simpler fix.
Two or more drains slow or backing up: Especially if they are in different rooms, this points to the main sewer line. A blockage there affects every fixture in your home. This is more urgent.
Toilet gurgling when you run the sink or shower: The gurgling is air displacement from a partial clog in a shared line. This is an early warning that a main-line blockage may be developing.

The Most Common Causes of Recurring Backups

1. Grease and Soap Buildup

Kitchen drains are the most frequent repeat offenders. Cooking grease, oils, and fats solidify on the interior walls of drain pipes as they cool. Over months and years they build up like plaque, gradually narrowing the pipe. Each snake job punches a hole through the mass but does not clean the walls — and the backup returns within weeks.

The real fix: Hydro-jetting — a high-pressure water stream that scours the interior pipe walls clean — is the only method that truly resets a grease-coated drain line to near-original diameter.

2. Hair and Soap Scum in Bathroom Drains

Bathroom drains accumulate hair, soap, and skin oils that bind together into solid plugs. These are more localized (usually in the P-trap or just past it) and easier to clear. A drain snake or even a drain cleaning tool (a plastic barbed strip) can usually pull out the clog.

If the bathroom drain backs up repeatedly despite clearing the trap area, the clog is deeper or soap scum has built up further down the branch line.

3. Tree Root Intrusion

This is a leading cause of sewer line problems in Central Texas neighborhoods with mature trees. Roots enter existing cracks or joints in older clay or cast-iron sewer lines. Once inside, they grow aggressively and can fill the entire pipe diameter.

Signs include: slow drains throughout the house, gurgling sounds, backups that return quickly after clearing, and outdoor areas with unusually lush or green patches of grass above your sewer line.

What it takes: Root cutting with a specialized blade attachment, followed by hydro-jetting to flush debris, and ideally a camera inspection to assess how much damage has occurred. Severely infiltrated pipe sections may need replacement.

4. Sagging or Bellied Pipe

Over time, soil shifts and drain pipes can sag or develop low spots — called "bellies." Waste slows down at the low point, solids accumulate, and backups happen regularly. This is not visible from inside the house; it requires a sewer camera to spot.

5. Partial Blockage or Foreign Object

A child's toy, excess toilet paper, wipes (even "flushable" ones), or accumulated debris can partially obstruct a line. These often cause a drain to work slowly rather than fail completely, and they recur if not fully extracted.

What You Can Try Yourself

Remove and clean the P-trap (the curved section of pipe under sinks). Place a bucket underneath, unscrew the slip-nut fittings, and pull it out. Clean it thoroughly and reinstall.
Use a drain snake (hand auger) for bathroom tub and shower drains. Push until you feel resistance, then rotate to either break through or hook the clog and pull it back.
Check the cleanout — the large capped fitting usually outside near your foundation. If it is full of water, the main sewer line is blocked and a plumber should be called immediately.

When to Call a Licensed Plumber

Multiple drains are slow or backing up at the same time.
The drain backed up within two to four weeks of being cleared.
You are seeing toilet gurgling or water backing up into a different fixture.
The cleanout outside is full.
Chemical cleaners have not helped.
You suspect root intrusion or have older clay pipes.

Alberto Plumbing offers professional drain cleaning throughout Pflugerville, Round Rock, Austin, and Hutto — including hydro-jetting and sewer camera inspection. Current promotion: $20 off drain cleaning. Call (512) 429-6933 — Jose A. Vital (TX Master Plumber M-39647) provides same-day service and upfront pricing.

Drain Keeps Backing Up: What Is Causing It and What to Do