Ryan Daugherty, Senior Facilities Project Professional and Michael Phifer, Department Manager at Terracon
Water penetration testing of doors, windows, and curtain walls often present challenges such asequipment, difficult transitions and interfaces. Existing solutions such manufactured spray racks that use pre-assembled components are popular in the market; however, issues such as high cost, low durability, limited configurations, and lack of special components significantly limit the effectiveness of these assemblies. Alternatively, low material cost, highly customizable spray racks that utilize off-the-shelf components are labor-intensive to fabricate and provide low durability.
To provide a solution to the challenges faced, Terracon explored the creation of a spray rack assembly using customized, durable spray nozzles and connectors combined with readily available, low-cost piping and fittingsto create a versatilespray rack. Our goal was to combine the efficiency of manufactured spray racks with the low cost and flexibility of custom rack fabrications.
The process began by using the experience of Terracon field testing specialists to create a list of components that were difficult to acquire, prone to malfunction or damage, or did not regularly perform as intended.
These components included the spray nozzle attachments and associated adapters and the tees for the spray rack “arms.”Terracon then fabricated relatively low cost, high-durability specialized replacement components using 3D printing(Photographs 1 and 2). This included digitally modelling components for their required performance,optimizing the models for rapid prototyping, and producing the components via the Fused Filament Fabrication 3D printing process.
Through this process, seven custom components, including an innovative quick connect assembly (Photograph 3),were developed. These custom components allow Terracon to quickly configure our spray rack assemblies to meet varying fenestration conditions, perform rapid in-field repairs and adjustments, and adapt according to the project requirements to meet our clients’ needs.
Our new customizablespray rack was recently utilized by Terraconto address the challenge ofwater testing a large mock-up wall assembly for a national healthcare provider.The specimen to be tested had an irregular shape containing a 90-degree inside corner andmeasured approximately 12 feet tall by 9 feet wide.Both the size and configuration of this specimen would have been challenging to test utilizing typical spray rack components. In general, large specimens are difficult to test because a typical hose bib connection may not provide sufficient water pressure and volume to achieve the test parameters.In addition, no components exist for typical spray racks which allow the spray rack to accommodate an inside corner.
However, the quickly interchangeable components of Terracon’s new system allowed for field adjustments, which included removing spray rack sections at the 90-degree inside corner where spray rack coverage was not necessary in order tomaximizethe available water pressure/volume.
The quick connect spray nozzles and lightweight components allowed the testing crew to easilymaneuverthe testing rack.In addition, the plastic-based construction of the rack (including both 3D printed and standard PVC components) reduced the potential to scratch or damage the façade materials.
Further capabilities are realized when specialty rope access is required.The light weight of Terracon’s custom spray rack assembly can easily be suspended utilizing typical rope access techniques.When a technician is also suspended to operate the assembly safely, window assemblies which are typically difficult to test become readily accessible.
Terracon’s innovative approach to spray rack design enables us to adapt to a continually changing market and provide excellent service to our clients.
About the Authors
Ryan Daugherty, RRO, REWO, CIT, sUAS Pilot is a senior facilities professional in the Charlotte, North Carolina, office. Certified as a roof and exterior wall observer, a Level I Thermographer, and a FAA sUAS remote pilot, Ryan has an extensive 21 years of experience in restoration, construction, estimating, and facility building enclosure consulting and testing.
Michael Phifer, RBEC, manages the facilities engineering group in the Charlotte, North Carolina, office. Michael has spent more than 10 years focusing on evaluation, design, and quality assurance services related to roofing and building enclosures.