By Brian Burton
Design/construction professionals can minimize their difficulties with onsite, or ‘in-situ,’ testing of fenestration components by adhering to certain well-established quality control (QC) principles that can reduce the chances of costly failures. However, there is little doubt onsite testing can be a complex undertaking.
The number of components encompassed within the scope of typical tests may account for at least part of this complexity. In addition to the fenestration products themselves, critical components include sealants, weatherstripping, and/or gaskets. Once the fenestration components themselves are included, along with environmental barriers and various components of the adjoining wall or roof assemblies, it is unsurprising the process becomes perplexing.
Many people tend to pay closer attention to product quality for component prototypes assembled specifically for laboratory testing than to products coming straight off the assembly line and shipped directly to the site. Adding to this challenge are several applicable standards, environmental problems that can be encountered onsite, and the general difficulties in attempting to successfully simulate a “severe weather event”—a challenging process even under controlled laboratory settings.
Further, fenestration components have likely been moved on numerous occasions before installation and testing. There is also the issue of movement caused by vibration, thermal deformation, or ultraviolet (UV) radiation. This knowledge offers good reasons to ensure products are protected from damage during storage, handling, and installation.
A general rule is to ensure the relevant parties know the applicable standards and testing methods. Both the requirements and the equipment are modified to keep pace with industry innovations, so it is important to know whether the most current ones are being used.
Aside from ensuring products are installed in accordance with the drawings, specifications, and building codes, close attention must be paid to the connection details between fenestration products and any water-resistant barriers (WRBs) in the wall or roof system. They must be properly ‘lapped’ to perform as intended. Failure to ensure continuity where systems components interconnect can be a potential source of air or water leakage during testing and during the building’s service life. When the test specimen or wall section is pressurized, air and/or water will manage to find a way to penetrate if there is a lack of continuity.
Another principle involves ensuring QC checks are completed before and during construction, as well as after project close-out. (After commissioning, maintenance instructions should be provided to the owner/operator.) These QC steps should include review of final construction documentation (including the shop drawings), arranging pre-construction/pre-installation meetings with individual trades, and confirming onsite construction inspection is adequate and regular.
The proper assembly, inspection, witnessing, and testing of a mockup that is inspected (and, ideally, photographed) before finishes are installed is also part of the overall systematic quality assurance (QA) process.
For installers, good building practice also involves ensuring onsite conditions are suitable when installing sealants and weatherstripping. This includes making certain surfaces are dry, clean, and free from contaminants such as dust or construction debris. Temperature may also be a factor in proper sealant application; stakeholders should pay attention to the manufacturer’s instructions. (This is another factor that should be addressed in pre-construction meetings.)
Many experts suggest design professionals should complete your own quality control inspections during delivery and installation. While this is rarely ‘mandatory,’ a product failing an onsite test can cost the project team both time and money. It is also good practice to have a representative present during onsite testing.
There are certain testing protocols that should be confirmed:
- Test specimens and locations should be examined for any damage or defects prior to commencing test setup.
- The test equipment should be calibrated, and the samples preconditioned (i.e. adjusted for ambient conditions to reduce adverse effects of wind and temperature onsite).
- The test equipment pressures should be checked during testing. Cycle times should also be monitored.
In many cases, onsite testing failures can often be traced to one or more of the following reasons:
- components were not properly installed (e.g. installers failed to read and follow the instructions);
- lack of experience or judgment by fenestration technicians and/or testing personnel;
- product or opening dimensions changed because components were transported to site, moved numerous times prior to installation, and exposed to weathering forces such as water, temperature fluctuations, and UV radiation;
- lack of sufficient detail in the construction documentation;
- problematic location of test specimens; and
- interfacing components were not properly lapped.
In-situ testing of newly installed fenestration is an effective means of confirming these products are installed in accordance with the drawings and specifications. As such, it is a benefit to all stakeholders involved. In the event of observed deficiencies or test failure, it also allows cost-effective remediation or replacement prior to building commissioning.
Brian Burton has written or co-authored several feature articles for Construction Canada, ranging from climate change’s effect on the built environment and the revitalization of Toronto’s Maple Leaf Gardens to specifying seismic restraints. He also publishes pieces on his site. Burton can be reached at firstname.lastname@example.org.