Technical Specifications
Information Sheet
General – Norbord OSB does not contain any added Urea Formaldehyde resins. For installation instructions refer to the APA’s Engineered Wood
Construction Guide E30U installation document and/or the appropriate building code and/or the design professionals specifications.
Information relevant to certification, span ratings, bond classification and mill identification are included in the APA grade stamp applied to
every panel when applicable.
Handling and Storage – Refer to the APA’s Engineered Wood Construction Guide E30U.
Exposure to Moisture – All rated Norbord OSB has an Exposure1 bond classification. Although panels should not be directly exposed to the
weather or moisture on a continuous basis, the Exposure 1 on Norbord OSB indicates that unprotected exposure during ordinary construction
periods will not adversely affect the structural properties. Exposure to adverse moisture conditions could result in edge swell. Sanding may be
required to level uneven edges prior to finish-covering application. Exposure to certain moisture conditions could also result in development of
mould and mildew.
Roof or Floor Sheathing – Norbord OSB used as roof or floor sheathing should be applied with the grade stamp facing down. Always read the
grade stamp for up-to-date information.
Installation – Follow the APA Engineered Wood Construction Guide E30U and/or your local building code or design professional’s instructions.
All panels must be spaced 1/8” along all edges (T&G panels are to be spaced 1/8” on the 4’ edges). Panels are sized to allow this spacing. Tip:
use a 10D nail as a space guide. For every continuous section of panels exceeding 80 feet in length, a 3/4” expansion point is required, refer to
E30U for details.
Nail spacing and type – Refer to the APA’s Engineered Wood Construction Guide E30U. Always consult your local building official for local
requirements and/or design professional’s instruction. Staples must be equivalent to the specified nails and may require different spacing
(refer to ESR-1539).
Adequate ventilation must be provided in unheated attics and crawl spaces. Net vent openings of at least 1/150
th
of the attic or crawl space
horizontal area are recommended. Attic ventilation should be divided equally between roof and soffit. Exhaust fans must be ducted outside the
structure.
Building codes require an impermeable moisture barrier on top of the ground cover in all crawl spaces.
Recommended Uses for Norbord OSB
This End-Use Summary outlines proper spanning capabilities recognized in the U.S. and Canada (as indicated). These uses are recognized
through leading code agencies in the U.S. and Canada. Regional codes are subject to periodic changes and local codes can vary widely. It is the
responsibility of the user to conform to current requirements of local building authorities.
Max. Support Spacing (in.) o.c.
Application
Structural
Use
Recommended
Thickness (in.)
U.S.
Applications
Canadian
Applications
Notes
Combination
Subfloor
Underlayment
*+
Sturd-I-Floor
/ Tongue
and Groove
19/32 T&G
5/8 T&G
23/32 T&G
3/4 T&G
7/8 T&G
1 T&G
1⅛ T&G
20
20
24
24
32
32
48
20
20
24
24
32
32
48
Apply panels perpendicular to supports. Combination
subfloor underlayment panels must have the T&G edges
lightly butted & the 4’ ends spaced
1/8”. Some joint
sanding may be required if panels are exposed to moisture.
Subflooring
+
Sturd-I-Floor
or Rated
Sheathing
7/16
15/32, 1/2
19/32, 5/8
23/32, 3/4
7/8, 1, 1⅛
16
16
20
24
32
N/A
16
20
24
32
Apply panels perpendicular to supports. If T&G panels are not
used, panel edges must be adequately blocked.
Space all
edges
1/8”. Cover with minimum ¼” underlayment
**
,
accepted lightweight or gypsum concrete
**
, structural wood
flooring
**
, or block edges.
Roof Sheathing
(Except for flat
roofs used as
walking decks)
Sturd-I-Floor
or Rated
Sheathing
3/8
7/16
15/32, 1/2
19/32, 5/8
23/32, 3/4
7/8, 1, 1⅛
24
24
***
32
40++
48
60
16
24
32
40++
48
60
Apply panels perpendicular to supports. Space all panels
edges
1/8”. Except where noted, edge support is required at
maximum spans. Use 2 panel H-clips between supports
spaced 48”. Tongue & Groove edges (⅝” & ¾”) or lumber
blocking. When used, H-clips aid in properly spacing the 8’
panel edges. Panels marked “Wall Use Only” are not to be
used in roof applications.
Wall Sheathing Rated
Sheathing
5/16
3/8 & greater
16
24
16
24
Panels may be applied parallel or perpendicular to supports.
High wind areas require panels to be installed vertically. Space
all panel edges
1/8”. All panel edges shall be supported by
blocking for wall sections used in lieu of let-in corner bracing.
Ceilings and
Soffits
Sturd-I-Floor
or Rated
Sheathing
3/8 & greater 24 24
Apply panels perpendicular to supports. Space all panel edges
1/8”. Protect the underside of the exposed Norbord OSB soffit
with a quality acrylic latex exterior paint system.
Utility Not
Applicable
1/4 16 16
No code approvals are available for structural uses. Excellent
Do-It-Yourself panels for decoration & general purpose use.
Space all panel edges 1/8”. For best results use blocking
along all edges and at mid length. A vapour barrier is
recommended on the warm side in wall paneling applications.
* Suitable as base for carpet, wood strip or parquet flooring only. The use of any vinyl flooring requires the use of an approved underlayment on top of the OSB Subfloor. ** Follow
material manufacturer’s instructions. *** Edge support not required at 24” span. + If finished floor is to be adhesive-bonded resilient flooring, always use an approved
underlayment, following the manufacturer’s instruction, over Norbord OSB. ++ Sturd-I-Floor max support spacing 32” o.c.