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.
🇹🇼 Expat Living Note: Home Repairs in Taiwan
If you are an international resident renting an apartment in Taipei, New Taipei, or anywhere in Taiwan:
- Voltage & Electrical Safety: Taiwan standard household voltage is 110V (60Hz). Do not plug 220V imported European/UK appliances directly without a certified step-up transformer.
- Plumbing Terminology: Local plumbers are called 水電 (Shuǐdiàn) and handle both water and electrical repairs.
- Landlord Obligations: Under Article 429 of Taiwan Civil Code, landlords are legally responsible for repairing natural wear and tear (such as hidden wall pipe leaks, water heater faults, or booster pump failures) unless explicitly waived in your lease.
Legal Disclaimer
The information provided on this website is for general educational and reference purposes only. For hazardous repairs involving live 220V electrical circuits, main gas lines, or structural wall drilling, always consult certified, licensed technicians. SOSfix disclaims any liability for personal injury or property damage resulting from DIY repair attempts.
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