This document details recommended practices for installing windows and doors, specifically addressing flashing and sealing materials to maintain water resistance. It references standards from organizations like AAMA (American Architectural Manufacturers Association) and ASTM International. The information is intended for use during installation of framed openings and emphasizes compatibility of materials and corrosion resistance of fasteners.
Scope and Referenced Documents
This practice focuses on the application and modification of water-resistive barriers and flashing materials around window and door openings. The document specifically references ASTM E2112, “Standard Practice for Installation of Exterior Windows, Doors and Skylights,” for sheathed wall installations. The document outlines definitions, significance, and use of these practices. The scope covers installations where modifications to the water-resistive barrier or flashing are required.
Material Compatibility and Corrosion Resistance
Compatibility of materials is a critical aspect of window and door installation. All materials that come into contact with each other – including coatings, flashings, and sealants – must exhibit chemical compatibility for their intended purpose, as outlined in AAMA 713. Metal products must be isolated from dissimilar or corrosive materials using a nonconductive coating or sealant. Fasteners used in the installation must be corrosion resistant, adhering to standards such as ASTM B456, B633, or B766, as specified by AAMA TIRA9.
Flashing Methods: Method A – Flashing Over the Mounting Flange
One method for applying flashing involves positioning it over the face of the mounting flange. This method, designated as Method A, requires a strip of approved flashing material – either mechanically attached or self-adhered – to be applied in a weatherboard fashion around the entire perimeter of the opening.
The process involves the following steps:
- Apply the first strip horizontally immediately below the sill, ensuring it extends past each side of the window.
- Cut the strip to a length that projects even with the vertical jamb flashing to be applied later.
Sill Flashing Installation
Specific attention is given to sill flashing installation. The top edge of the sill flashing must be fastened or adhered to the framing. When mechanically attached, fasteners should be placed along the edge of the rough opening where they will be covered by the window’s mounting flange during installation.
Crucially, the lower edge and the last 230 mm (9 inches) of each end of the sill flashing should not be fastened or adhered. This allows the water-resistive barrier applied later to be slipped up and underneath the flashing in a weatherboard fashion, enhancing water protection. Figure 2 in the referenced document illustrates this technique.
Jamb and Head Flashing
Jamb flashing (illustrated in Figure 4A) and head flashing (illustrated in Figure 5) are also applied using Method A. The flashing is applied in a weatherboard fashion around the perimeter of the opening. The document does not provide specific details regarding the application of head flashing beyond its illustration.
Water-Resistive Barrier Application
The primary water-resistive barrier is applied by others, as indicated in Figure 6. The document emphasizes the importance of repairing any damaged flashings or water-resistive barriers before installing the exterior wall surface to ensure continuity between the existing barrier and the new materials.
Post-Installation Procedures
Following installation, several post-installation procedures are necessary:
- Check the window for proper operation and locking mechanisms.
- Ensure that flashing materials are covered by the installation of the exterior wall surface within a timeframe recommended by the flashing manufacturers.
- Repair any damaged flashings or water-resistive barriers before installing the exterior wall surface to maintain continuity.
- Maintain a minimum gap of 6 mm (1/4 inch) between components.
Backing Support
The document includes a figure (Figure 1A) illustrating backing support attached around the perimeter of the rough window opening. However, no descriptive text accompanies this figure within the provided source material.
Sheathing Considerations
In applications where wall sheathing is used, the document notes that sheathing must be applied prior to flashing and window installation. This is highlighted in Figure 3A, which depicts window installation (Method “A”).
Significance and Use
The document emphasizes the significance of these practices in maintaining the integrity of the building envelope and preventing water intrusion. Proper flashing and sealing are essential for long-term performance and durability of window and door installations.
The provided source material is insufficient to produce a 2000-word article. Below is a factual summary based on available data.