Are Casement Windows Better in Stormy Weather?

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In regions with complex climates such as the Middle East and coastal areas, the choice of window type plays a key role in improving the wind pressure resistance and protection performance of buildings. In recent years, sliding windows have gradually become the preferred window type in modern building design due to their excellent storm resistance, good sealing performance and high energy efficiency. This article will explore in depth how sliding windows perform better than other window types under storm conditions and explore their practical application value in commercial buildings.

I.Three main damage mechanisms faced by windows in storm conditions

Storms can damage windows in three main ways, posing a potential threat to the integrity and safety of building structures:

  • Wind-borne flying objects – High-speed flying debris in a hurricane, such as tree branches or building debris, can hit and shatter unreinforced window glass or damage window frame structures.
  • Air pressure differences – Strong winds create a pressure difference between the inside and outside of windows, which can easily cause window frames to deform or loosen.
  • Rainwater infiltration – In an environment with strong winds and rainfall, windows with poor sealing performance are prone to rainwater leakage, causing indoor structures to become damp or damaged.

According to building disaster statistics for the 2023 Florida hurricane season, failure of window systems is one of the main causes of indoor water infiltration, structural damage, and property losses. Multiple tests and field evaluations have shown that sliding windows perform better in extreme climate conditions. Their multi-point locking structure and high-performance sealing system can effectively withstand the combined impact of high wind pressure and heavy rainfall. Compared with sliding windows and double-hung windows, sliding windows perform better in resisting wind pressure deformation and rainwater infiltration, and have stronger overall weather resistance. Especially in medium and large commercial projects, sliding windows can not only effectively reduce the probability of damage during storms, but also save maintenance and operating costs in the long run.

Recommendation: Choose casement windows that have passed ASTM E1886 and ASTM E1996 tests to significantly improve their ability to withstand high wind pressure and flying debris impact.

II.Why are sliding windows structurally designed to be more storm-resistant?

Sliding windows can form a highly compressible sealing structure in the closed state through single-sided hinges and outward opening, effectively improving its protection capabilities under extreme weather conditions such as wind pressure and rain:

  • Multi-point locking system – the window is evenly fixed to the window frame through multiple locking points, dispersing the external wind pressure to avoid concentrating on a certain part, thereby enhancing the stability and impact resistance of the entire window under strong winds.
  • Tightly compressed sealing strips – when the window is closed, it forms a high fit, which can effectively prevent air leakage and rainwater infiltration, making the indoor temperature more stable, thereby reducing energy consumption and improving overall energy efficiency.
  • High frame strength – when encountering strong wind updrafts or lateral impacts, the window body can still remain stable and not deformed. Compared with sliding window structures, it is more reliable and less likely to loosen or move.

Ps: Compared with sliding windows, sliding windows rely on active locking and mechanical pressure to improve the wind pressure rating.

III.Performance comparison between sliding windows and other window types

The window structure directly affects the building’s ability to withstand storms. The following is a comparison of several common window types:

Window Type Storm Resistance Energy Efficiency Wind Pressure Rating
Casement Window
High (ASTM E1886 Certified)
High (Strong Sealing)
Excellent (>50 psf)
Double-Hung Window
Moderate
Moderate
Average (35–40 psf)
Sliding Window
Low
Low
Poor (<30 psf)
Fixed Window
High (Non-Operable)
Very High (Seamless Sealing)
Excellent (>60 psf)
  • Double-hung windows are opened by sliding up and down, and a certain movable gap must be left between the window sashes for operation. When the external wind pressure increases, these movable parts are prone to micro-displacement, resulting in the inability of the sealing strip to maintain stable compression, thereby increasing the risk of air infiltration and rainwater leakage.
  • Sliding windows are opened and closed by moving the window sash along a horizontal track. In order to maintain smooth operation, their structure usually cannot achieve tight compression with the window frame. At the same time, most sliding windows are only equipped with a single-point locking device, which is prone to loosening or deformation under the action of wind pressure. The overall wind resistance is weak and is not suitable for high-rise or building facades with high wind pressure intensity.
  • Fixed windows cannot be opened, and their surrounding structures can achieve high compression, so they have excellent sealing performance and wind pressure resistance. However, because they cannot be opened, they do not have natural ventilation functions, nor can they be used as escape routes in emergencies, and their application scenarios are relatively limited.

Recommendation: It is recommended to use fixed windows and sliding windows in combination to give full play to their respective advantages: fixed windows can provide excellent sealing and wind pressure resistance, while sliding windows can meet ventilation and emergency opening needs. The combination of the two can help improve the safety of the building in extreme weather and the flexibility of daily use.

IV.Does professional installation determine the wind resistance of windows?

If the installation is not standardized, even if high-performance window products are selected, it may lead to problems such as poor sealing and abnormal structural stress, so that the overall performance cannot meet the expected standards.

  • The installation of windows must comply with ASTM E1886 and E1996 standards. These two specifications have clear requirements for wind pressure resistance and impact resistance, respectively, and are the key basis for ensuring that doors and windows play a protective role in extreme weather.
  • In highly corrosive environments such as deserts or coastal areas, it is recommended to use hardware accessories with anti-corrosion properties to effectively resist the long-term erosion of salt spray, moisture and wind and sand on the window connection parts, extend the service life and maintain structural stability.
  • The window must be fully integrated with the building’s exterior enclosure system and watertight system to prevent leakage.

Recommendation: Windows installed with uncertified accessories are 38% more likely to leak or break. Choosing our products can provide you with door-to-door installation services.

V.Sliding Window Care and Maintenance Guide

To maintain the storm resistance and energy efficiency of sliding windows, clean and inspect them regularly:

  • Regularly clean the window tracks and seals to remove dust, sand and salt accumulation in time to effectively prevent component wear, jamming or corrosion, extend the service life of the window and maintain the sealing effect.
  • It is recommended to check the window locks and seals regularly every 6-12 months to check for aging, looseness or loss of elasticity to ensure that the window still has good security and sealing effect.
  • It is recommended to lubricate the hinges and connectors every year to reduce wear and avoid jamming, so as to ensure smooth and stable operation of the window during opening and closing.

In hot or sandy environments, seals age faster, and regular inspections can reduce maintenance costs.

Recommendation: Use UV-resistant silicone every two years to protect the external seal line and extend the service life.

Additional comparison chart: Sliding windows vs. double-hung windows for wind resistance

Feature Sliding Window Double-Hung Window
Storm Resistance
Low
Moderate
Sealing Technology
Basic (Track-Based)
Moderate (Dual-Sash Compression)
Wind Pressure Rating
Poor
Average
Ventilation
Good
Good
Maintenance Frequency
High (Track Prone to Wear)
Moderate

Conclusion：

In regions with strong winds, frequent sandstorms, or seasonal hurricanes, casement windows are undoubtedly a high-performance and cost-effective solution. Their exceptional storm resistance, reliable window sealing technology, and high energy efficiency make them particularly well-suited for modern commercial buildings.

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