How to customize curtain wall against water penetration in applications？

Curtain wall construction has played a vital role in the modern building for a long time. And curtain wall buildings are so popular in a variety of applications both in commercial and residential fields. How to customize curtain wall against water penetration plays critical role in keeping the safety, thermal performance and comfort of the structure and residents.

Wind Driven Rain and Likelihood of Water Ingression
There are five different types of forces such as gravity, kinetic energy, capillary action, surface tension and air pressure difference that contribute either partially or as a whole to the ingression of water. In most cases, the ability of curtain wall systems to withstand forces that increase water intrusion possibility is generally based on glazing details, drainage details, frame construction, weather stripping and frame gaskets, perimeter flashings, sealings and interior sealants. Wind loads generate pressure differentials which may lead to windblown rain that surpass gravity force and consequently force water to move upward. Surface tension properties and capillary effect of curtain wall elements are considerably influenced by thermal expansion of different building materials. Take structural glass curtain wall for an example. Expansion or contraction of materials due to temperatures may tight expansion joints excessively and eventually increase capillary action between various components of glass curtain wall systems in applications. Meanwhile, structural glass curtain wall surface tension properties may vary due to contraction and expansion and lead to undesired results. Therefore, it is necessary for you to design movable joints, seals and gaskets in order to make rooms for differential movements between different members.

Design of Curtain Walls to Control Water Penetration
In recent years, there are different types of curtain wall systems to employ different techniques to prevent water penetration. It is important for the designer to get much more information from a professional curtain wall manufacturer to prevent undesired situations. We would like to have a discussion about curtain wall systems to prevent water ingression in the following sections:
1. Structural Silicone Glazed System
This system generally has the most severe performance requirements for sealant adhesion and water penetration at exterior-face and frame-glass interface. In structural silicone system, moisture ingression is controlled through the provision of cavities that force water to weep holes at the stack joint.
2. Unitized Curtain Wall System
Unitized curtain wall system is placed using pressure equalizing principle that disrupts forces which push water across barrier. The air pressure differential is a major force that drives rainwater into the curtain wall assembly. This force is blocked by pressure equalized concept that composed of airtight self-contained compartments and air vents permits air pressure to vent and equalize and finally discharge any moisture at the sills which might penetrate the system.
3.Stick Built Curtain Wall System
The water proofing performance of stick built curtain wall system is dependent on the completeness and integrity placement process of seals at shear blocks and glazing gaskets at glass interior side in addition to pressure plates that need to be placed appropriately. The diversion of water from vertical to horizontal pressure plate is generally conducted at zone plugs.