Meeting the Standards: Douglas Fir Siding, produced by Roseburg Forest Products Co., is manufactured according to the U.S. Department of Commerce's PS 1-95 Voluntary Plywood Product Standard, and meets the requirements of HUD's Use of Materials Bulletin, UM-64. These standards specify requirements for veneer grades, veneer species, glue bond requirements, thickness tolerances, workmanship, and construction.
Panel Construction:
| Siding
Thickness |
11/32”, 15/32”, 19/32” |
| Siding
Grade |
Clear, Premium, Sound |
| Face Veneer
Species |
Douglas
Fir |
| Innerply and Back
Veneer |
Western Softwoods |
| Adhesive |
Exterior type, fully waterproof phenolic
glue* |
|
Flame Spread
Rating |
R.F.P.’s Douglas Fir Siding yields an average flame spread
index of 126.2, well within the Class III (C) flame spread range of
75-200. |
|
Glue Bond
Testing |
PTL/PSI initially performed strenuous tests on Douglas Fir
Siding for glue durability, including a 9-cycle boil test. Currently, APA performs
routine vacuum tests on Douglas Fir Siding. R.F.P.’s Douglas Fir Siding
has met or exceeded all testing
requirements. |
|
Thickness
Tolerances |
Douglas Fir Siding meets allowable shear values for wind and
seismic forces according to the 1997 UBC. |
|
Shear
Values |
Douglas Fir Siding meets allowable shear values for wind and
seismic forces according to the 1997 UBC. |
| Approved Span Ratings |
11/32" at 16" o.c.
19/32" (4 and 8" groove) at 16" o.c. RB&B and Plain at 24
o.c. |
