W20 "CLASSIC"
Originally developed to replace single-glazed and puttied-steel windows that were common from the 1890s to the 1960s, W20 can accommodate 1/4” plate glass through 5/8” insulated glass. W20 is an excellent choice for interior doors, separating walls, and specialty exterior doors as well as exterior fenestration that requires a historic look. W20 is accepted by the National Park Service and Department of the Interior for specific steel window replacement on properties listed on the National Register of Historic Places.
FEATURES
- 1-1/4" profile depth
- 1-1/8" wide true muntin divider
- 3/4" wide muntin divider available with putty glazing
- Lock-in glazing bead with EPDM spline
- Glazing range 1/4" to 5/8"
- Two-layer powder coat finish
- Double weather-stripping
-
Values (5/8” IG):
- Casement
- U-Factor: .44
- SHGC: .22
- Air/Water/Forced Entry: R-PG35
- Fixed
- U-Factor: .33
- SHGC: .26
