Overview
Fenestration is a penetration in the wall system and the WRB system strategy selected in STEP 3A. Therefore, it is important to effectively integrate the selected WRB system strategy with the fenestration. This is done by flashing and, where needed, detailing to provide fenestration support.
Proper integration involves flashing material specification and installation detailing for flashing and support/anchorage of the fenestration. Such integration must coordinate the window manufacturer’s installation instructions and material specifications, the WRB manufacture’s installation instructions and material specifications, and the flashing manufacturer’s installation instructions. Building codes do not and cannot necessarily provide specific requirements due to the vast number of acceptable material and detailing options. Thus, building codes tend to give general requirements reflective of the performance intent – keep water out of the wall.
Fortunately, there are a variety of credible resources to support proper integration of fenestration and flashing with the selected WRB system strategy on walls that use FPIS-ci.
IMPORTANT TIP: When considering flashing details provided in the design resources that follow, also consider revising the WRB selection (STEP 3A) as needed to arrive at the best-value flashing, window installation, and WRB system for your project.
DESIGN RESOURCES: The design resources shown in Table 4 are applicable to the WRB strategies also listed in Table 3.
Resources
- Technical Evaluation Report: Attachment of Windows with Integral Flanges Through Foam Plastic Insulating Sheathing to Wood Framing
- Residential Windows Topical Library
- Commercial Windows Topical Library
TABLE 4
Design and Detailing Resources for Fenestration Installation and Flashing based on WRB Strategy
| WRB Strategy | Design/Detailing Resources & Installation Instructions |
| FPIS-ci used as the WRB |
|
| Separate WRB layer applied behind FPIS on wall substrate | AAMA 500 Standard - $70 for non-members |
| Separate WRB layer applied over FPIS and directly behind cladding | AAMA 500 Standard - $70 for non-members |
| Dual WRB: FPIS-ci is used as the primary WRB layer with a separate WRB layer applied behind FPIS | See resources for WRB Strategy #1 above and combine with WRB Strategy #2. |
For additional information on window installation on walls with FPIS-ci, refer to Continuous Insulation for Residential Windows.
IMPORTANT TIP: An ANSI/ABTG FS 200 standard is in development, which will feature standardized window and door installation methods for walls with FPIS-ci. Currently, many window manufacturer installation instructions do not specifically address use of FPIS-ci on walls. The ASTM E2112 standard for window installation also currently does not address window installation procedures for walls with FPIS-ci. Therefore, the above resources are provided as accepted practice based on successful use, testing, and expert advice. Where appropriate, seek professional advice and consult with the applicable window, WRB, and flashing component manufacturers.