Is it useless to put tape on windows during a typhoon? Home Office Wind Tunnel Experiment Revealed: A Guide to Correct Wind Protection Measures and Tempered Glass Upgrades

The "X-shaped tape" that is stuck every year during the typhoon season is actually wrong

Whenever a typhoon warning is issued, many families in Taipei and New Taipei will dig out paper tape or kraft tape and paste "X", "meter" or even "well" shapes on the window glass, believing that this can prevent the glass from breaking. This practice has been popular in Taiwan for decades and has almost become a Taiwan defense ritual. However, the results of rigorous tests conducted by the Architectural Research Institute of the Ministry of the Interior in a wind tunnel laboratory surprised many people - Glass with tape on it is more likely to break than glass without tape.

The reason is the so-called "stress concentration effect" in physics. When the tape is adhered to the surface of the glass, it will change the way the force is distributed when the glass is subjected to wind pressure. When wind pressure acts on the entire piece of glass, the stress that should be evenly distributed is concentrated at the junction of the edge of the tape and the glass frame due to the constraints of the tape, forming a structural weakness. The result is that at the same wind speed, the tape-covered glass reaches the breakage threshold faster than the bare glass.

Is the tape completely useless? The only effect is to "reduce scattering"

Strictly speaking, tape has one function: When the glass has broken, tape can reduce the chance of the fragments flying around and injuring people. But it is completely useless to prevent the glass from being blown by strong winds. In other words, if your purpose is to prevent windows from being broken during a typhoon, applying tape is not only a waste of time, but may also be counterproductive.

Many masters engaged in plumbing, door and window installation in Shuangbei said that in the window repair cases received after the typhoon, many of the glass with tape on it was still broken, and the homeowners had to spend more time to remove the residual glue and debris.

A truly effective anti-typhoon glass solution

Instead of spending time on applying tape, it is better to fundamentally improve the wind resistance of the windows. The following are three mainstream practices currently recognized by Taiwan’s building doors and windows industry:

1. Laminated Safety Glass: This type of glass has a layer of PVB or SGP adhesive film sandwiched between two layers of glass. Even if it is broken by external force, the fragments will stick firmly to the film and will not break into sharp, razor-shaped fragments like ordinary glass. It is currently recognized as the most suitable glass choice for typhoon protection, and has been adopted in many windward windows of new buildings.
2. Tempered Glass: After being heated at high temperatures and then rapidly cooled, the strength is about 4 to 5 times that of ordinary glass. When broken, it will break into smaller round granular fragments, which are less likely to cause serious cuts. Be aware, however, that tempered glass cannot be cut on site and must be pre-cut to the correct size at the factory.
3. Safety Film: If you do not want to replace the entire glass, you can affix a professional explosion-proof film on the inside of the existing glass. The effect is similar to the principle of glued glass, which can stick the fragments together when broken. Quality varies greatly on the market, so it is recommended to purchase products that are thicker than 4mil (approximately 0.1mm) and pass ANSI Z97.1 or EN 12600 safety test standards.

Window frame hardware is the invisible key to preventing typhoons

Many people only care about whether the glass will break, but ignore the problem of the window frame itself. In the Taipei Basin and New Taipei coastal areas, typhoons bring not only strong winds, but also large amounts of entrained horizontal heavy rain. If the airtightness and watertightness of the window frame are insufficient, rainwater will pour into the room through the gaps in the window frame, even if the glass is intact.

The following inspections are recommended before the typhoon season:

• Window sash tightness: After closing the window, run your fingers around the edge of the window frame. If you can clearly feel air leakage, it means that the airtight strip has aged, hardened, deformed, and needs to be replaced.
• Hinges and Pulleys: If the pulleys on a sliding window are stuck or skewed, the sash will not close completely. If the hinges of the sliding windows are loose, strong winds may directly blow the sash open or even blow it off.
• Silicon Caulking: If the silicone between the window frame and the wall has cracked, fallen off, or turned moldy and black, it will lose its sealing effect. Re-silicon is the most common and most economical way to prevent leaks.

The wind pressure resistance of different grades of aluminum windows is very different

According to CNS 11527 standard, the wind pressure resistance rating of Taiwanese aluminum windows ranges from 360S to 500S. The 360S level can withstand wind pressures approximately equal to level 10 winds, while the 500S level can withstand wind pressures above level 17. For general residences in the greater Taipei area, it is recommended to use at least 360S grade aluminum windows; if your home is on a high floor (above the tenth floor) or is located on the windward side, it is strongly recommended to upgrade to 440S or even 500S grade.

Conclusion: Put down the tape and do the right thing

The habit of putting tape on windows during typhoons is like many people’s belief that they should take vitamin C when they have a cold. It sounds reasonable, but the actual effect is limited or even counterproductive. What can truly protect you and your family is to choose the right glass material, maintain the window frame hardware, and keep the silicone caulking intact. Doing these things before the typhoon comes is the most pragmatic investment in typhoon prevention.