[The water pipe in the kitchen of the medieval house is clogged] The drain hole regularly bubbles and vomits, and the grease becomes cement and gets stuck? Analysis of blind spots for high-pressure water jet cleaning water pipes (high-pressure flushing) and cleaning ports (Cleanout)

Daily disaster in the old apartment in Shuangbei: the kitchen drain suddenly "vomits water"

In many second-hand apartments in Taipei City and New Taipei City that are over 30 years old, the kitchen sink drains slowly, the drain hole makes a "gurgling" bubbling sound, and even in the middle of washing the dishes, brown sewage with a foul odor suddenly pours out from the floor, which is a scene that gives countless families nightmares. Many homeowners will immediately go to the store to buy concentrated sulfuric acid or caustic soda and other chemical pipe clearing agents and pour them into the bottle. As a result, instead of opening the water pipe, the water pipe will deform and leak. Or they will find a traditional pipe master to use an electric steel wire to pull the water pipe, and the water pipe will become stuck again within two months. To eradicate frequent blockages in kitchen water pipes, we must clarify the physical truth behind "grease saponification and cementation" and adopt correct modern water and electricity cleaning methods.

Chemistry Facts: Why do "stones" grow in kitchen water pipes?

Kitchen wastewater contains a large amount of cooking oil, animal fat and dishwashing detergent. When the high-temperature oil soup flows down the drain pipe, the water temperature will drop rapidly as the pipe extends into the wall. During the cooling process, grease will adhere to the inner wall of the PVC water pipe and chemically react with the calcium and magnesium ions in the water and the alkaline components in the dishwashing detergent. This process is called "Saponification".

After years of accumulation, the saponified grease will form into white-brown lumps as hard as limestone (commonly known as "grease oil lumps" or "water pipe cement"). These oil lumps will reduce the diameter of the original 2-inch water pipe to only the thickness of a finger. Any tiny food residue passing through will instantly cause a large blockage.

Fact check: Dispelling the deadly myth about "strong acid and alkali chemical conduits"

Many people are accustomed to using strong acid (concentrated sulfuric acid) or strong alkali (high concentration sodium hydroxide/caustic soda) pipe clearing agents when water pipes are blocked. This is a very dangerous operation in the eyes of water and electricity engineers:

• Thermal deformation and melting of PVC water pipes: Strong acids or alkalis react with water at extremely high temperatures (temperatures can reach as high as 80°C to over 90°C). The old thin-walled PVC drainage pipes in the old Shuangbei apartments are completely unable to withstand such high temperatures, which will cause the water pipes to soften and deform, and even the joint glue to dissolve and fail, causing massive water leaks inside the wall!
• The oil block becomes harder after the chemical reaction: If the strong alkali cannot completely dissolve the high concentration of heavy oil block, it will form a hard saponified paste in the pipe that is more difficult to remove, making the difficulty of pipe routing exponentially higher.

Modern hydropower treatment methods: high-pressure water jet cleaning vs. traditional steel wire pipes

When the kitchen water pipe is stuck due to oil block, professional plumber technicians will use the following modern construction methods to completely cure it:

1. Traditional electric wire pipe stripping (machine scraping): Use high-speed rotating spring steel wire to drill into the pipe to break up the oil. The disadvantage is that the steel wire can only penetrate a small hole in the middle of the oil block (treating the symptoms but not the root cause). The thick oil blocks around the pipe wall are still attached and will be clogged again after a few months.
2. High-Pressure Water Jetting:Using a pressure washer equipped with a special inverted nozzle, high-pressure water jets of up to 150 to 200 bar are inserted deep into the water pipes. The reverse thrust generated by the inverted spray water column will drive the nozzle to automatically advance, using a 360-degree high-pressure water network with no dead ends to completely crush and wash away the hardened oil attached to the PVC pipe wall, returning the inside of the water pipe to a state close to that of a new pipe (a root cause solution).
3. Full-process monitoring of pipe endoscopes: Before and after cleaning, a high-resolution pipe endoscope camera is inserted to instantly confirm on site whether the oil lumps in the pipes have been completely removed, and to check whether the water pipes are broken or have reverse slope.

The key to preventing pitting during decoration: a "Cleanout" plug must be reserved

For homeowners who are undergoing plumbing renovations in old houses, plumbers and electricity technicians emphasize that they must install "cleaning ports" when piping:

Conclusion: Use scientific cleaning methods to maintain smooth waterways

It is no small matter that kitchen water pipes are clogged and backed up. Blind use of strong acid pipe cleaners will only lead to greater disasters that damage the pipelines. Eliminate the traditional pipe cleaning method that treats the symptoms but not the root cause, use high-pressure water jets to completely peel off the oil on the pipe wall, and insist on reserving standard cleaning plugs during decoration. Only then can we say goodbye to the nightmare of kitchen drainage and vomiting, and create a clean and odorless high-quality living environment.

The latest standards for catching leaks and regulatory responsibilities in Shuangbei collective housing (2025-2026 practice)

According to Article 10 of the "Apartment Building Management Regulations" of the Ministry of the Interior and the trend of civil water leakage judgments in Shuangbei District Court in recent years, most water leakage disputes in old collective housing focus on the identification and definition of "exclusive parts" and "common parts". The roof platform and the public pipes are jointly owned by all separate owners, and the repair costs should be shared by public funds or all residents in proportion to their shares according to law; if the water supply and drainage pipes inside the floor slabs on the upper and lower floors are damaged, the pipes will be borne exclusively by the users or shared by the upper and lower floors.

At the engineering and technical level, modern professional leak detection has fully introduced non-destructive scientific testing, including "FLIR high-resolution infrared thermal imaging camera" (locating temperature difference leakage paths), "high frequency moisture meter" (measuring the moisture content of deep structures) and "pipeline air pressure and water pressure pressure test" (determining whether hot and cold water pipes are leaking). During construction, do not directly apply elastic cement or oil-based paint on the wet cement layer to seal it. Otherwise, the thermal expansion of internal water vapor will quickly cause the coating to blister and peel off, resulting in more serious powdery wall cancer. The standard construction method must first completely eliminate the water source, wait until the moisture content of the cement structure drops below 8%, and then apply the negative pressure resistant silicic acid permeability crystallized waterproof layer.

Recommendations on independent certificate storage and compensation process for water leakage repair

1. Take photos and videos as evidence immediately: Use rulers to record the leakage range, frequency of water discharge, direction of water mark diffusion, and keep time stamps.
2. Written notification and coordination survey: Officially notify the neighbors through the management committee or a certified letter, and agree on a professional third-party leak detection and appraisal unit recognized by both parties to conduct an on-site survey.
3. The contract states the warranty terms: When signing the contract for the project, be sure to clearly specify the waterproofing warranty period (usually 1 year for partial repairs, and 2 to 5 years for the whole room or roof re-construction), and specify the water test acceptance criteria (such as a 48-hour water storage test in the bathroom shower area) to protect your own asset rights.