Glass Curtain Wall Construction
A glass curtain wall is a facade that only carries its own dead load and does not carry any dead loads from other buildings. The loads are shifted via the columns of the buildings or connection to the floor to the main structure. This type of architectural facade is made to resist water infiltration, air, seismic forces, wind forces, and the pressure from its own dead load forces.
There are many types of glass curtain wall construction methods. Opaque colored sheet glass or clear glass are usually used for the panel material. Flat glass is usually used in entrances and windows to stabilize the load. Ordinary sheet glass is not affected by the sun, so thermal breakage is not a concern. However, heat absorbing glass will develop problems via thermal stress due to temperature differences around the area. These problems can be fixed by paying attention to the glass edges. Before starting any glass curtain wall construction, the glass needs to be checked for any chip that could cause a thermal break.
By using extended aluminum members, curtain walls are designed in an efficient manner. The frame is then filled with glass, which gives the building an environmental control and provides an architecturally pleasing sight to the building. Instead of glass, curtain walls can also be filled with vents, stone veneer, louvers, operable windows, and metal panels. Curtain walls are different than storefront systems in that the design requirements consider the contraction and thermal expansion, they are designed for multiple floors, water diversion, thermal efficiency for heating, lighting in the building, cooling, and building movement and sway.
Most buildings before the mid-20th Century were made with exterior walls that sustained the load of the entire building. With the invention of new structural concepts via building cores and shear walls, the exterior walls do not have to sustain high dead loads and can be designed as much lighter than steel or brick facades. The more efficient design gave way to the glass becoming an exterior facade, thus creating the modern glass curtain wall. Overall, glass curtain walls are high performance systems that require little maintenance with relative ease.