Building envelope is the exterior structure of a building which protects it from the external forces like weather and other natural elements. In a more systematic definition, it is the arrangement of engineering and architectural elements comprising of the ventilation, structural, temperature control systems. They come together to form one cohesive system. And when this system fails, it is known as building envelope failure.
An envelope designed with coordination and consultation from all the expert parties involved including the workmen will always have a slim chance of encountering a failure. But building envelope failures happen all the time. The reasons are many and unless a forensic structural engineering company completes the investigation, it is hard to pinpoint the exact cause of the failure.
What’s Considered Failure?
- Moisture penetrating the envelope and walls during construction
- Glass elements failing over time leading to fatal consequences
- Pure structural damage to support systems like arches, pillars, and others
All of these are the results of failure. There could be many reasons but here are the top 4 reasons why building envelops fail-
This occurs when the contractor, engineer or any other person involved in the project, make design choices that are not appropriate. Altering the weight, density, or any metric against the manufacturer defined limits, will bring in results that were not intended.
Materials have certain criteria for structural change, resistance or penetration. Altering these values will only lead to performance degradation.
The material itself can have problems from the start. There could be a change in the required performance levels due to inadequate storage facilities or it can have manufacturing defects. These are mostly inescapable if not dealt in time.
Most worksites that bring in lots of construction material never plan out their storage. When these materials remain in contact with natural elements for prolonged periods, change in physical build-up occurs. The results will deviate from the manufactured defines specifications.
These are human errors that are usually caused by poor training or skills, lack of proper supervision or due to lack of communication among involved parties. Most of the business envelope failures are the result of poor workmanship or human-caused errors.
It may happen that many structural components were not installed according to the manufacturer specifications or there was an alteration of the directions. Even worse, there could be no directions or instructions provided by the supplier.
Natural Elemental Issues
It is easy to build a house but it is difficult to build a house that can stand against the ruthlessness of natural elements. No matter how perfect the installation is, or how perfect the manufacturing was when a storm, hurricane or a flood arrives, it will change the structural properties.
Strong natural elemental changes like extreme cold or heat, unanticipated moisture, or extreme weather can lead to all of the above-mentioned causes. It can create deltas between design and implementation, alter the material properties and affect human installations.
Even though this sounds serious, most business envelope failures are not caused by natural elements. Human and design flaws still constitute the majority of problems. So it is important to inspect and supervise all the construction and hopes it survives nature.