Mark Meshulam is an expert witness and consultant for windows, glass and building facades, including laboratory and field testing.


Laboratory and field testing are an important – some would say integral – part of the window business, both in the realms of product certification for individual window units and also for the prove-out of full assemblies.

For product certification such as AAMA and NFRC, specific-sized windows are placed in test chambers and tested using methods and criteria which are according to an organized set of performance levels.
For testing of larger scale custom construction, however, there is little that is truly standard from one test to the next.

The Architect or Consultant designs a test specimen and selects test methods and criteria specifically for each project.

This specimen is then tested in specialized laboratories, such as the Construction Research Laboratory in Miami, Mid America Testing in Catawissa, MO, or Quast Consulting & Testing in Mosinee, WI.

The test specimen, or mockup, is often designed to be a representative sampling of conditions found on the project, bringing together as many unique features of the wall construction (such as fixed, operable, sliding doors, swing doors, inside and outside corners) into one assembly as is feasible.

Isometric drawing of mockup for Avenue East project, Chicago
Isometric drawing of mockup for Avenue East project, Chicago

We, the window contractor, then create a full set of shop drawings for the mockup. When approved, the mockup is released for fabrication and a custom sized chamber is built in a test facility. Then, with material, drawings and tradesmen, we go to the lab, build the mockup, and test it.

The amount of attention, effort, work and expense involved in mockup tests make them seem almost like a job unto themselves.

Avenue East mockup under construction
Avenue East mockup under construction

Building a typical window mockup often takes about a week, but a complex assembly such as Avenue East’s mockup took much longer due to the size and composite nature of the assembly. Testing can also take one week or many.

The beauty of building a mockup is having the ability to really study unique conditions and make adjustments before going into production.

A mockup also gives design professionals and owners a chance to see a piece of their building many months before it will be built in its ultimate location.

Avenue East mockup completed and ready for testing
Avenue East mockup completed and ready for testing

If problems arise in the testing, delays and redesigns can result. I have seen full mockups torn down and replaced if fundamental problems arose in the testing.

As surprising as this may seem, it is infinitely better than erecting a building and then discovering its fatal flaw after it is completed.

One of the most exciting aspects of laboratory testing of custom wall assemblies is the dynamic water test. It combines huge volumes of water with high, buffeting winds delivered by none other than an airplane engine!

If your specimen passes this test, you should have a very good product indeed!

Now you can be inside the test chamber during the dynamic water test. Watch our video:

Need to discuss testing for your project?

Mark Meshulam, Chicago Window Expert, in a pensive moment
Mark Meshulam, Chicago Window Expert, in a pensive moment


3 thoughts on “The Dynamic Water Test”

  1. The windows are elegant. You surely planned it very well.

    A water feature will fit to add more attraction. The elegance and beauty will surely predominate.

  2. Glass Test w/ unexpected results

    # 1993: Garry Hoy, a 38-year-old lawyer and a senior partner at the Holden Day Wilson Law firm in Toronto, Canada, fell to his death on July 9, 1993, after he threw himself against a window on the 24th floor of the Toronto-Dominion Centre in an attempt to prove to a group of visiting law students that the glass was “unbreakable.” His first attempt failed to damage the glass at all. On his second attempt the glass still didn’t break, but popped out of the window frame, and he fell over 300 feet to his death.[125][126]

    Perhaps a candidate for the “Darwins”

    Go to wikipedia List of unusual deaths

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