[Fireproofing between pipes in an old house renovated] Is there water leakage in the pipes and a strange smell? "Fireproof mud layer plug protection between pipes" and "single-layer independent exhaust" modifications must be made when renovating a medieval house

Hidden threats between pipes: leaky wall cancer, viruses and stack effect fire spread

In old buildings and apartments in Taipei and New Taipei, the "Pipe Shaft/Utility Chase" is a public passage that runs longitudinally through the entire building's water supply pipes, drainage risers, sewage pipes and bathroom exhaust pipes. However, the early construction quality was uneven. When the pipes of many buildings penetrated each floor, the annular gap between the floor and the pipes was not sealed or blocked, forming a huge "vertical cavity" that led directly to the top floor. This will bring about three major hidden hazards: First, when the water pipes on the upper floors break, the water will flow down along the risers between the pipes and seep out at any floor that is not tightly sealed, causing serious wall leakage in the ceiling of that floor; second, when the neighbors The odor from smoking in the toilet, using the toilet, and even viruses will flow back into your own bathroom through the air pressure difference between the pipes; thirdly, once a fire breaks out on a low floor, the pipes will turn into smoke exhaust channels, and the fire and highly toxic smoke will rush into all high floors along the gaps within a few minutes, easily causing heavy casualties.

A must-do when renovating a historic house in the bathroom: "Fireproof mud layer plugging between pipes" construction

In order to block the water, gas and fire routes, when the bathroom walls are removed during renovation of a medieval house, "Firestopping" must be performed on the internal floor slabs between the pipes. The standard protection methods are as follows:
1. Cleaning and anti-rust primer: Remove concrete gravel and debris around the floor through-holes between pipes, and apply anti-rust paint to the exposed iron pipes or structural steel bars to protect them.
2. High-density rock wool filling (bottom support): Around the pipeline, tightly fill "fire-resistant rock wool (Rockwool)" with a thickness of at least 10cm in the pores of the floor slab, as a support bottom support for subsequent pouring materials.
3. Pour fireproof non-shrinkage cement or fireproof sealant: Pour fireproof non-shrinkage cement mortar (thickness at least 5cm) above the rock wool to prevent water seepage and cracking.
4. Fireproof mud and fireproof sealing coating (Firestop Caulk): Fill the annular gap at the junction of the pipeline and the cement with an intumescent "fireproof sealant (fireproof mud)". When encountering a high-temperature fire, the fireproof mud will expand several times, completely sealing the cavity left after the pipeline is burned, preventing the smoke and fire from spreading upward. Through the construction of this layer of plugs, even if there is water flowing down between the pipes, it will be blocked by the waterproof cement and drained directly along the main pipe without leaking into the home.

"Single-layer independent exhaust" and installation of windproof check valve to prevent odor backflow construction method

In order to solve the problem of odor recirculation in the bathroom of the building, the exhaust configuration of the bathroom ceiling exhaust fan must be modified to "Single-floor Ventilation":
1. The traditional approach is to tuck the exhaust fan hose directly between the ducts. When retrofitting, a core drill should be used to drill a 4-inch vent hole in the balcony or exterior wall. Directly guide the exhaust hose of the exhaust fan to the outdoors to completely isolate the odor from the pipes.
2.If it is not possible to open a hole for discharge and must be discharged into a pipe, a set of "electric check valves" linked to the exhaust fan power supply must be installed in the exhaust pipe. When the exhaust fan is turned off, the check valve will be driven by a small motor to achieve 100% airtight closure, blocking the return flow of odor and smoke inside the pipes; when the exhaust fan is started, the valve will automatically open to exhaust. At the same time, the fan should be upgraded to a three-in-one or four-in-one "bathroom warm air dryer" equipped with heating, drying and powerful exhaust functions to ensure that the bathroom is dry and smell-free all year round.

The impact of pipe room engineering quality on the acquisition, rental and sale valuation of old properties

For investors and real estate developers who acquire entire old apartments and revitalize them into partitioned suites, fire prevention and odor-proofing projects between pipes are the "invisible key" to protect the rental ceiling of the asset and prevent legal disputes.
If after a suite is rented out, tenants frequently complain about the smell of smoke, feces and urine in the toilet, or water leakage in the adjacent bathroom, it will lead to a high rental cancellation rate and directly damage the property's net operating income (NOI). During the renovation, the work team was required to install "fireproof mud plugs between pipes" and "independent exhaust with electric check valves" in the bathrooms of each room. Although each bathroom will increase the material wages by about 5,000 to 8,000 yuan, it can establish a "three-proof safety net" for the property to prevent leakage, odor and spread of fire. In the Shuangbei second-hand housing trading market, providing construction records and photos showing that fireproof and fireproof sealing has been carried out between pipes is a strong selling point to prove to high-end buyers that the structure of the house is safe and the concealed work is up to standard. It can enable the property to obtain a higher premium when it is sold. It is a technical insurance that cannot be ignored in real estate investment.

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 a contract for a project, be sure to clearly specify the waterproofing warranty period (usually 1 year for partial repairs, and 2 to 5 years for complete 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.