Problem: Water penetration.
Water can penetrate through the joints of vinyl and metal siding, soaking insulation and deteriorating framing members and interior finishes.
Cause: Poor detailing and construction of joints between siding strips at corners and around windows and doors.
- Drain water away, and prevent the flow of water through the joints of vinyl and metal siding, by taking the following precautions:
- Follow the manufacturer's instructions for installing the siding as shown in Figures 38a and 38b.
Figure 38a - Joint Details For Metal And Vinyl Siding - Allow space for expansion of siding panels.
- Note 1: Place nail 3 to 4 inches (75 to 100 mm) from edge.
- Note 2: Slide notched cutout 1 inch (25 mm) under adjacent strip.
Figure 38b - Joint Details For Metal And Vinyl Siding - Allow space for expansion of siding panels.
- Note 1: Pre-molded joint-finish accessories allow for thermal movement.
- Note 2: Leave 1/4 inch (5 mm) between edges of siding.
- With diagonal siding, cut the joints perpendicular to the ground and overlap the lower strip with the upper strip as shown in Figure 39.
Figure 39 - Diagonal Vinyl Siding
- Note 1: Cut joints vertically and use proper accessories to finish the joints.
- Note 2: Vinyl siding at 45 degrees.
- Note 3: Lap sheathing paper over flashing.
- Note 4: Caulk sides and under sill.
Figure 40a - Pre-Molded Corner Details For Aluminum, Vinyl, And Wood Siding
- Ensure that all joints in alternate courses are staggered by at least 36 inches (900 mm).
- Take the following precautions to ensure that corner recesses drain water away from the interior.
- Use only pre-molded corner-piece accessories on every outside corner. Figures 40a and 40b show typical corner details as suggested by manufacturers.