When drains are slow, the solution isn't always just clearing the individual drain itself. If multiple floors experience drainage issues simultaneously, what you actually need to find is where the water ultimately merges, and whether the blockage lies in a branch line or a shared downstream sewer line.
Drains Slow on Both Floors: The Problem Lies Beyond the Surface
For this project, we visited a residential townhouse in Donggang, Pingtung. Drains on both the first and second floors were draining sluggishly. If we had only snaked a single drain repeatedly, we would have likely only poked a temporary hole in the clog without removing the deep build-up lining the pipe walls.
Yong Zheng began by analyzing the symptoms, the layout between the floors, and the pipe pathways before guiding our CCTV pipe camera into the line. The footage clearly showed heavy grease and scale scale deposits, which had severely narrowed the internal diameter needed for water and air to flow smoothly.
Our technician utilizes a CCTV pipe camera to locate the blockage and assess the condition of the wastewater lines.Before cleaning: Scale and grease cling heavily to the pipe walls, choking the drainage capacity.
PROFESSIONAL CORNER｜DRAINAGE NOTE
Where Water Backs Up Isn't Always Where the Clog Is
In multi-story townhouses, the first and second floors often have separate branch lines that eventually discharge into a shared main stack. When this downstream shared line is constricted by grease and scale, a large flow from the second floor pushes water and air downward. This pressure often finds relief at the lowest, easiest escape path—the first-floor floor drains—causing bubbling, odors, or backups.
STEP 01
2nd Floor Heavy Flow
Wastewater rushes down the vertical stack into the shared pipe.
STEP 02
Constricted Main Line
Accumulated scale lacks the volume to pass both the water and displaced air.
STEP 03
1st Floor Symptoms
Air bubbles up, odors escape, or water backs out from the lower floor drains.
Therefore, a backing-up drain on the first floor doesn't mean the problem is localized there. The actual restriction is often further downstream in the shared wastewater line. This is why multi-story drainage issues require professional CCTV diagnostic testing.
02｜SOLUTION
Not Just Draining the Line, but Restoring the Pipe Walls
After assessing the pipes, Yong Zheng determined the ideal water pressure and nozzle angle for the pipe diameter and material. We ran the high-pressure hydro-jetting line through the system segment by segment, scouring the walls clean, and then verified the results with a final water-flow test and camera check.
01｜Identifying Access Points & Sewer Layout
Locate cleanouts and usable drains on both floors to formulate a safe, non-destructive cleaning route.
02｜Multi-Stage Hydro-Jetting
Flush the pipe walls with high-pressure water jets, shearing off years of scale, grease, and sludge, and washing the debris out of the line.
03｜Flow Testing & Camera Verification
Perform heavy water flow tests and use the endoscope to ensure no scale remains and the pipe structure is sound.
Combining hydro-jetting with real-time camera inspection ensures the pipes are scoured completely clean.Live video feeds confirm clean, smooth pipe walls, eliminating guesswork from our service.
03｜RESULT
Restoring the Entire Wastewater Pipeline
Resolving multi-floor townhouse drainage requires reviewing individual fixtures as part of a single unified system. This project successfully completed floor inspections, CCTV diagnosis, multi-stage hydro-jetting, and post-clean flow verification.
We Clear More Than Just the Immediate Clog
Confirmed the link between the 1st and 2nd-floor drain symptoms.
Used CCTV endoscopes to map out deposits, bends, and suspicious pipe sections.
Deployed high-pressure hydro-jetting to wash away decades of grease and hard scale.
Conducted heavy flow tests to guarantee the system drains beautifully.
RELATED CASES
Every Drain Blockage Tells a Different Story
Even though drains present similar slow-flow symptoms, the underlying culprits and locations vary wildly. Explore how Yong Zheng approaches other diverse residential and commercial cases.
Case 1 | Townhouse Main Line
Sanmin District Townhouse: Outdoor Main Sewer Jetting
The homeowner noticed pooling and odors, but our camera tracked the issue to heavy calcified scale in the outdoor main sewer. Problems don't always stay indoors.
Water was backing out of a first-floor drain, but the root cause lay deep in the underground shared wastewater line, showcasing how the backup point isn't always the clog point.
Chronic pooling in a yard drain led us to find dense roots growing right into the pipe joints. Different clog materials require completely different mechanical tools to clear.
If drains are slow on both floors, does it mean they share the exact same clogged pipe?
Not necessarily. Townhouses have complex piping layouts where individual branch lines eventually merge into a shared sewer stack. We diagnose the connection points using specialized CCTV sewer cameras to locate the true bottleneck.
What is the difference between hydro-jetting and standard snaking?
Standard mechanical snaking is designed to punch a hole through a soft blockage to get water flowing again. High-pressure hydro-jetting, however, scrubs the entire interior of the pipe walls clean of grease, scale, and build-up, restoring original pipe volume.
Why is water or air bubbling up from my first-floor drains?
When a downstream main sewer line is constricted, waste from higher floors displaces air and water down the stack. Lacking space to pass, the pressure forces air and wastewater out of the lowest, nearest openings, which are usually first-floor drains.
Does hydro-jetting wastewater pipes require tearing up walls or flooring?
Almost always, we utilize existing drain grates or cleanout ports to run our hydro-jet lines, avoiding any structural damage to your flooring or walls. Tearing up flooring is only considered as a last resort if a pipe is structurally collapsed.
Does Yong Zheng serve Donggang and Pingtung areas?
Yes. Yong Zheng Environmental Engineering offers professional plumbing and drain jetting services throughout Pingtung County, including townhouses, apartments, shops, and commercial kitchens. For non-emergency cleanings, booking in advance is highly recommended.
