The material war for waterway renovation: from traditional PVC to modern new pipes
When renovating old apartments or decorating new houses in the greater Taipei area, the planning of the waterway system is the "core project" that directly determines the lifespan of the residence. In the past, old residential buildings in Taiwan often used galvanized iron pipes or ordinary PVC plastic pipes as hot and cold water pipes. The former is prone to rust and leaks red water, while the latter has poor heat resistance and is prone to embrittlement and cracking due to high temperatures. In modern interior decoration, most people have switched to stainless steel pipes. However, if you often watch foreign decoration programs or YouTube videos, you will find that plumbers in European and American countries almost all use a plastic pipe with bright colors (red represents hot water, blue represents cold water) and is as soft as wires - this is "PEX pipe (cross-linked polyethylene pipe)". What is the difference between this pipe, which has a penetration rate of over 80% in Europe and the United States, and the mainstream stainless steel crimped pipes in Taiwan? Which one is the best solution for renovating an old house in Taiwan?
Get to know European and American newcomers: the principles and advantages of PEX cross-linked polyethylene pipes
PEX is modified from high-density polyethylene (HDPE) through a "cross-linking reaction" by physical or chemical methods. The cross-linked molecular structure changes from the original linear chain to a network, which greatly improves its resistance to high temperature, high pressure and chemical corrosion. The reason why PEX pipes have taken the European and American markets by storm is due to its unique physical properties:
1. High flexibility and "Home Run" water distribution plate construction method: This is the biggest advantage of PEX pipes. Because it can be bent like a wire, plumbers can use the "whole roll cable" construction method when piping, and directly pull a connectorless PEX pipe from the source "Water Distributor (Manifold)" to the shower room, sink or toilet. This means "absolutely no pipe fittings (like elbows, tees)" inside the concrete walls or floors. More than 90% of water pipe leaks occur at joints. Without joints, the risk of water leaks in the wall is reduced to zero.
2. Anti-freeze, anti-cracking and water quality safety: PEX pipes have slight elasticity. When water freezes and expands in a cold environment, the pipe wall will expand slightly without bursting; and the plastic material will never rust or release heavy metals, ensuring the purity and health of drinking water.
3. Extremely fast construction speed: Using exclusive expansion (Expansion) or crimp ring (Crimp) tools, a connection point can be completed in a few seconds, without the need for blowtorch welding or waiting for the welding glue to dry.
Taiwan’s Steel King: The strength of double-crimped stainless steel pipes (white iron pipes)
Unlike Europe and the United States, which prefer plastic pipes, Taiwan’s hydropower projects rely most on “stainless steel crimped pipes” (usually SUS304 or SUS316 medical-grade materials) for hot water pipes and high-end water supply pipelines.
1. The structure has extremely high strength and is not afraid of external knocks: During the subsequent decoration of old apartments in Taiwan, there is often a need to nail hanging picture frames, lock heavy objects or perform cement construction. Stainless steel pipes are extremely hard and can withstand a certain degree of accidental damage from drilling or knocking; while PEX pipes are essentially plastic and will burst and spray water immediately once nailed or scratched by a sharp tool.
2. Impeccable heat resistance and pressure resistance:Double-crimped stainless steel pipes use professional hydraulic clamps to tightly crimp the pipe fittings and rubber O-rings on the pipeline. They can withstand pressures up to more than 10 kg/cm², and under the continuous circulation of high-temperature hot water, the metal pipe body will not have any thermal expansion and contraction deformation problems.
Why is it difficult for PEX pipes to thrive in Taiwan’s hydropower market?
Although PEX pipes are very good in Europe and the United States, when they are introduced to repair old houses in Shuangbei, Taiwan, they will face three huge practical bottlenecks:
1. It is extremely difficult to obtain parts and hardware: This is the most fatal pain point. In Taiwan's building materials, hardware stores and plumbing materials stores, the shelves are filled with stainless steel crimp fittings and PVC pipe fittings. If PEX pipes are installed in your house, if local damage occurs and needs to be repaired in the future, the plumbers will not be able to buy special PEX connectors and tools, and most plumbers will not have dealt with this material. Subsequent maintenance will become a serious orphan pipeline.
2. Intolerance to ultraviolet rays (the tube must not be exposed): The molecular structure of PEX pipes is easily damaged by ultraviolet rays, and it will become brittle and crack after being exposed to the sun for several months. Many pipes in Shuangbei Old Apartment are run on the back balcony, top floor or exterior wall. This is absolutely prohibited in the PEX system, which greatly limits its use scenarios.
3. Material costs remain high: Currently, only a handful of agents in Taiwan have introduced high-end PEX pipe systems. From special distributors, expansion tools to the pipe itself, the overall quotation is much higher than that of the already highly standardized and domestically produced stainless steel crimping system.
The cost duel between the two and the ROI evaluation of decoration investment
We take the redrawing of hot and cold water pipes in a 30-square-meter house with 3 bedrooms and 2 bathrooms as an example to compare the costs of the two:
* The reasonable price in Taipei for joint work and materials (including wall construction and white iron crimping pipe material configuration) is about NT$ 80,000 to NT$ 130,000, the market is fully competitive and the quotation is transparent.
* Since original pipes and water distribution trays (Manifolds) must be imported from abroad, and special casings (pipe-in-pipe design to facilitate direct replacement of inner pipes in the future) must be used, the overall hydropower construction quotation usually starts from NT$ 180,000, and can even reach more than NT$ 280,000.
[Business and Investor Perspectives]
For commercial merchants who want to buy a house, renovate it and then resell or rent it, the whole house equipped with PEX pipe-in-pipe system can be marketed as an "American century-old seamless water supply system" to increase the property premium, but from the perspective of long-term maintenance costs and value preservation, Because stainless steel pipes have the most complete ecological chain of water and electricity maintenance in Taiwan, any water and electricity shop in the alley can repair them, which greatly reduces the long-term ownership and maintenance risks of the property in the future.
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
- 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.
- 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.
- 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.
