Glazing systems and weather resistance: designing for climate

Weather resistance is an important part of any glazing system. Learn how manufacturers design for wind, rain, snow and worse.



All glazing systems are built to withstand basic weather conditions. After all, there'd be little use in a window, door, screen or curtain wall that let in rain, hail or snow.

But not all glazing systems are built equally. Some are designed specifically with weather resistance in mind.

In this context, weather resistance covers the basic ability to withstand wind and rain. But it also covers resistance to ultraviolet (UV) radiation and temperature fluctuations. This is to ensure structural integrity and prevent leaks, corrosion and decay, no matter the weather.

Making a glazing system weather-resistant involves comprehensive testing for watertightness, air permeability and wind resistance. Without these tests, glazing systems wear away in bad weather and become less energy-efficient.

Weather-resistant glazing systems use factory-sealed insulated glass units (IGUs) or specialist glass,  along with high-performance structural sealants, specialised gaskets and drainage systems called "weep holes".

These components work together to create a barrier that's watertight, airtight and wind-resistant, as well as protect against rain, hail and snow.

Here are some key ways that glazing systems are made weather-resistant.

Sealing and bonding

All glazing systems are sealed and bonded. But glazing systems built for weather resistance use advanced sealing and bonding methods such as double seals, structural silicone and wet or dry glazing.

IGUs use a double-seal process. The primary seal (usually polyisobutylene) prevents moisture from entering and gas from escaping from the air gaps. Meanwhile, the secondary seal, typically made from silicone or polysulfide, provides structural strength.

Many modern facades use structural-grade silicone to bond glass directly to the frame. This creates a watertight seal that allows movement from wind, thermal expansion and environmental vibrations.

Wet glazing uses high-performance sealants or putty to create a long-lasting and watertight bond. Dry glazing, meanwhile, uses rubber gaskets or pre-formed tapes to secure the glass. This is easier and quicker to install and replace than wet glazing.

Moisture control and drainage

Most glazing systems are exposed to rain, condensation and cleaning water. Moisture control and drainage are required to direct this away from the frame and interior. Without these measures, water can accumulate, damaging the structure and sometimes causing it to fail.

There are several ways that weather-resistant glazing systems control moisture and drainage. The first involves filling the spacers between glass panes with a desiccant that absorbs trapped moisture. This prevents interior fogging and condensation, which – if left unchecked – can lead to mould growth.

Framing systems are also designed to be drained and pressure-equalised. This means any water that penetrates the outer seal is captured and channelled out through weep holes in the bottom transom.

Finally, warm-edge spacers are used to reduce heat transfer (known as "thermal bridging"). Typically made from polymer or stainless steel, the spacer minimises cold spots where condensation could form.

Material selection

The material used to make the frame contributes to weather resistance. Aluminium, uPVC, composite materials and steel (our material of choice) all protect against rot and moisture, especially when fitted with thermal breaks.

Coatings can also be applied to increase weather resistance. Frames are powder-coated to prevent corrosion. This powder coating is marine-grade in harsh coastal environments.

The glass, meanwhile, can be coated with a low-emissivity (low-E) coating. This regulates the surface temperature and reduces the temperature differences that can lead to condensation.



Structural integrity

If a glazing system is installed in an area prone to extreme weather, special measures must be taken to ensure structural integrity and weather resistance. In these instances, laminated glass is used instead of IGUs (although laminated IGUs do exist).

Laminated glass is made by bonding two sheets of glass with a plastic interlayer. If the glass breaks, it's designed to stay in its frame, providing some residual protection against wind and water ingress.

In high-rise and high-wind areas, glazing systems with deeper fixing profiles and stronger anchorage systems are used. This helps withstand significant wind loads.

Finally, high-performance curtain walls are fitted with pressure-equalised rain screens. That means the pressure inside the glazing is equal to the pressure outside. This stops rain from entering the building.

Special types of glazing

We've already seen that glazing plays an important role in weather resistance, whether as an IGU or laminated installation. Two types of specialised glass also contribute to weather resistance: self-cleaning glass and heated glass.

Self-cleaning glass has a coating that breaks down dirt with UV rays and lets rain wash away what remains. This helps maintain visibility and performance in areas where windows are likely to get dirty from rain, snow and other environmental conditions.

In extremely cold areas, glazing systems are made with heated glass. This involves applying a metal oxide coating that prevents snow and ice from building up.

Weather-resistant glazing systems from Wrightstyle

At Wrightstyle, we manufacture a range of weatherproof windows, screens and curtain walls. All are made from steel and glass and protect against heat loss and weather damage.

We recognise the importance of weather resistance as a means to protect building interiors from wind, rain and heat transfer and ensure long-term structural integrity. All our systems are designed to prevent mould, condensation and costly repairs and are built for energy efficiency.

And like all our products, our weather-resistant glazing systems are tested and certified, ensuring that your project meets relevant industry compliance standards.

Are you looking for a weather-resistant glazing system for a door, window, screen or curtain wall? Get in touch with Wrightstyle for comprehensive product and technical advice.