Field testing installed fenestration units should always be included as a specification requirement. It is critical to perform a test on one of the first units installed to establish a baseline for the rest of the required testing and confirm detailing is weathertight before full installation begins. It is also important to include testing at different milestones of installation as a quality control (QC) measure to check for consistency as the project progresses.
Specifying the required test pressures for air and water penetration in the contract documents is best practice for all team members to know exactly what the designer expects on the day of the test, as is explicitly stating the passing criteria for the test. It also prevents ambiguity when it comes time to perform the test and ensures all parties are on the same page.
The specification should include the parties who must witness the field test, including, at a minimum, the designer, installer, and manufacturer. If a leak is discovered, having team members who understand the tested system and specific installation witness the test helps determine the cause and associated corrective measures and avoid ad-hoc repairs, such as adding sealant to get the system to pass.
Drawings
The drawings allow the designer to show the intent for the fenestration system and any specific detailing they want to include to help maintain the four barriers, including water, air, thermal, and vapor continuity across the building. Often, the drawings allow for a much simpler explanation than describing different fenestration components in the text within the project specifications.
An important component of the fenestration details in the drawings is showing the proposed system in the documents. This allows the detailing
to be project specific and show the basis-of-design window profile and associated anchorage, instead of using a generic window frame and anchors that will be different from what is installed on the building. This is most important for perimeter detailing and showing how the adjacent construction will tie in with the intended fenestration product. Including generic frame profiles or, worse, profiles for a different type of system (e.g. storefront versus punched windows) can lead to both performance and cost issues during construction.
Sill pan flashing
When it comes to fenestration systems, one of the most critical components to show outside of the actual system is the flashing. The flashing acts almost like part of the fenestration in terms of water management. Sill flashing is particularly important since most window leaks originate from or end up at the sill. However, flashing installation is also one of the most contested aspects of a new building. This article discusses flashing for three types of fenestration systems: punched windows, window wall systems, and curtain wall systems.
