24 Mar 2020

Evaluating Performance and Integrity of the Building Envelope

Air leakage, water penetration, and structural performance are just three of numerous considerations encountered when selecting components for building projects.  Performance mock-ups can provide peace of mind to those involved with a building project to ensure the building envelope can withstand extreme conditions.  However, there are numerous steps that must be taken before, during, and after testing to ensure that the mock-up is successful.  It is best to gain an understanding of how mock-up testing can provide insight into how your exterior building products and systems will perform once installed and exposed to extreme conditions. 

Mock-ups consist of part of a building that is constructed either on- or off-site to set a standard for the project, whether it be visual, performance, or both.  A performance mock-up will undergo a series of testing, including static air infiltration, static and dynamic water penetration, structural performance/wind loads, seismic, and in some cases thermal cycling and condensation resistance.  Because the full test procedure can be very complex, and the mock-up involves large test specimens with multiple trades, knowing the steps to preparing, installing, and testing a mock-up is key.

Prior to installation, the area of the exterior wall to be represented must be determined.  This should include any transitions, corners, or balconies and any dissimilar wall types.  Each trade responsible for each of the mock-up elements must be able to work together off the single mock-up drawing.  Likewise, the parties involved should review the project's performance requirements and test methods such as any pretesting, the deflection criteria, design pressures, and pass/fail criteria.  These same parties will be involved in the installation and testing of the mock-up at the lab, so it is important that they are involved from the start. 

Ensuring each party involved understands the project's performance requirements is also essential.  Test methods and performance criteria, as written in the test lab's formal test procedure, should be reviewed and approved by each trade prior to the chamber being built by the test lab.  Project requirements for chamber design, pretesting, deflection criteria, design pressures, pass/fail criteria, etc. will be listed in the test procedure that is written off the project specification.  A trade would not want to be surprised after installation with a test requirement that their product may not be able to achieve. 

Additional items to consider:

  • Coordination of material delivery and trade installation schedule
  • Supervision of curtain wall manufacture
  • Inspection of test chamber prior to commencing installation
  • Determination of any special equipment required for installation

Being prepared for a performance mock-up up front will not guarantee a passing system, but it will ensure that all parties agree with the installation, testing, and desired outcomes and will provide a smoother process for everyone involved.  For more insights on the benefits to a successful mock-up, download our complimentary webinar recording


Tyler Westerling,
Senior Project Engineer,
Intertek Building and Construction


Tyler Westerling is a Senior Project Engineer with Intertek's Building and Construction team in Fresno, California, where he has worked for more than 15 years. He has developed diverse testing expertise in many areas of the B&C business, including thermal performance, air infiltration, water penetration, and structural performance, among many others.  He is responsible for mock-up and field testing. He graduated from San Francisco State University and holds professional engineering licenses in the states of California and Florida. 

You may be interested in...