A drain that clogs repeatedly is telling you the blockage was never fully removed — or that something structural keeps rebuilding it. The usual culprits are grease and soap scale coating the pipe walls, tree roots entering the sewer line at a joint, a sagging (bellied) section of pipe, or decades of buildup in old cast iron. Snaking pokes a hole through the problem; fixing it means finding which cause you have.
- A recurring clog is a symptom, not bad luck — something keeps rebuilding the blockage.
- Grease never goes down the drain 'hot enough' — it cools and coats the pipe farther along.
- Tree roots are the #1 cause of repeat main-line clogs in older Valley neighborhoods.
- A camera inspection turns guessing into knowing — you see exactly what's in the line.
- Hydro jetting cleans the pipe wall itself; snaking only opens a channel through the clog.
Why does the same drain keep backing up?
Because the cause is still in the pipe. A drain snake (auger) bores a channel through a blockage and gets water moving again — but the grease layer, root mass, or scale ring it punched through stays behind and starts catching debris the same day. If your kitchen sink or main line backs up every few months on schedule, you're not unlucky; you're on a rebuild cycle.
What actually causes recurring clogs?
- Grease and soap scale: fats cool and solidify on pipe walls well past the kitchen, narrowing the line a little more with every wash-up.
- Tree roots: roots follow moisture into tiny gaps at sewer pipe joints, then grow into a net that catches everything. Clay pipe, common in mid-century San Gabriel Valley homes, is especially vulnerable.
- Bellied or back-pitched pipe: a sagging section holds standing water and sediment that re-forms a clog after every clearing.
- Aging cast iron: decades of internal rust and scale leave a rough, narrowed channel that snags waste.
- "Flushable" wipes: they don't break down like paper — the FTC has taken action over exactly this claim — and they weave into root masses and rough pipe walls.
How do I find out which cause I have?
A sewer camera inspection. A waterproof camera travels the line and shows — on screen, recorded — whether the problem is roots at a joint, a belly holding water, scale, or a collapsed section. It also locates the trouble spot precisely, so any repair is a targeted dig instead of an exploratory trench. We include camera work in our sewer services, and we show you the footage, not just a verdict.
What's the difference between snaking and hydro jetting?
Snaking is mechanical: a rotating cable opens a hole through the clog. It's fast and right for one-off blockages near a fixture. Hydro jetting uses high-pressure water to scour the full circumference of the pipe wall — grease, scale, roots, sludge — restoring the line to its original diameter. For recurring clogs, jetting followed by a camera check breaks the rebuild cycle instead of restarting it. Compare both in detail in our snaking vs. hydro jetting guide, or head straight to drain cleaning service.
What can I do to prevent clogs between cleanings?
- Scrape grease into the trash and wipe pans with a paper towel before washing.
- Use sink strainers in the kitchen and shower; empty them, don't rinse them down.
- Nothing goes in the toilet but waste and toilet paper — no wipes, regardless of the package.
- Run hot water for 15–30 seconds after using the kitchen sink.
- Skip chemical drain cleaners: caustics damage older pipes and rarely clear the real blockage. The EPA's WaterSense program is a good reference for fixture-friendly practices.
About this guide
From the Good News Plumbing & Drain Inc. team — family-owned and serving the San Gabriel Valley since 2001. California C-36 License #906746 (verify it at cslb.ca.gov), bonded & insured, and backed by our satisfaction guarantee. Guidance reflects the plumbing we repair and install across the Valley every week. Last reviewed July 16, 2026.
Common questions
Are chemical drain cleaners really that bad? +
For recurring clogs, yes. Caustic cleaners generate heat that stresses old metal and PVC joints, they rarely dissolve the full blockage, and they make the line hazardous for whoever works on it next. Mechanical cleaning solves what chemicals only postpone.
How often should a main sewer line be cleaned? +
There's no universal schedule — it depends on the pipe's age, material, and tree cover. A line that's been camera-verified clean may go many years; a clay line under mature trees may need annual maintenance jetting. The camera tells you which house you live in.
Do tree roots mean my whole sewer line needs replacing? +
Not necessarily. If the pipe is structurally sound, cutting the roots and jetting the line — sometimes with a spot repair at the entry joint — can buy years. A collapsed or badly deteriorated line is a different conversation, and the camera footage makes it an honest one.
