| Span Ratings APA RATED SHEATHING, APA RATED STURD-I-FLOOR and APA RATED SIDING
carry numbers in their trademarks called Span Ratings. These denote the maximum
recommended center-to-center spacing in inches of supports over which the panels
should be placed in construction applications. Except for APA RATED SIDING panels, the
Span Rating applies when the long panel dimension is across supports, unless the strength
axis is otherwise identified. The Span Rating of APA RATED SIDING panels applies when
installed vertically.
The Span Rating on APA RATED SHEATHING panels appears as
tow numbers separated by a slash, such as 32/16, 48/24, etc.(a) The left-hand number
denotes the maximum recommended spacing of supports when the panel is used for roof
sheathing with the long dimension or strength axis of the panel across three or
more supports. The right-hand number indicates the maximum recommended spacing of
supports when the panel is used for subflooring with the long dimension or
strength axis of the panel across three or more supports. A panel marked 32/16,
for example, may be used or roof decking over supports up to 32 inches on center or for
subflooring over supports up to 16 inches on center.
The Span Rating on APA RATED STURD-I-FLOOR and APA RATED
SIDING panels appears as a single number. APA RATED STURD-I-FLOOR panels are designed
specifically for single-floor (combined subfloor-underlayment) applications under carpet
and pad and are manufactured with Span Ratings of 16, 20, 24, 32 and 48 inches. The Span
Ratings for APA RATED STURD-I-FLOOR panels, like those for APA RATED SHEATHING, are
based on application of the panel with the long dimension or strength axis across
three or more supports.
APA RATED SIDING is available with Span Ratings of 16 and
24 inches. Span-rated panels and lap siding may be used direct to studs or over
nonstructural wall sheathing (Sturd-I-Wall construction), or over nailable panel or lumber
sheathing (double wall construction). Panels and lap siding with a Span Rating of 16
inches may be applied direct to studs spaced 16 inches on center. Panels and lap siding
bearing a Span Rating of 24 inches may be used direct to studs 24 inches on center.
All RATED SIDING panels may be applied horizontally direct to studs 16 or 24 inches on
center provided horizontal joints are blocked. When used over nailable structural
sheathing, the Span Rating of APA RATED SIDING panels refers to the maximum recommended
spacing of vertical row of nails rather than to stud spacing.
For a description of Span Ratings under the Canadian
Standard for Construction Sheathing, refer to the APA Product Guide: Performance Rated
Panels Meeting the Requirements of CSA-0325, Form CE T500.
(a) Exceptions are APA RATED SHEATHING intended for use as
wall sheathing only, and APA RATED WALL BRACING. The trademarks for such panels contain a
single number similar to the Span Raging for APA RATING SIDING.
How to Order APA Panels
Sanded and Touch-Sanded Panels:
Designate thickness, APA trademark, grade, Group number (b),
exposure durability classification, dimensions, number of pieces. For example:
• 3/4" APA A-A, Group 1, Exterior, 48" x
96", 100 pcs.
• 3/8" APA Underlayment, Group 1, Exposure 1,
48" x 96", 100 pcs.
(Designate "sanded face" if touch-sanded grades
are to be used under resilient flooring, or see Table 11 for additional grades.)
(b) Underlayment and C-C Plugged panels 1/2 inch and
thicker are generally span rated and do not contain species group number in trademark.
Designate Span Rating.
Performance Rated Panels:
Designate thickness, APA trademark, grade, Span Rating, exposure durability
classifications, dimensions, number of pieces. For example:
• 15/32" APA RATED SHEATHING, 32/16, Exposure 1,
48" x 96",100 pcs.
• 23/32" APA RATED STURD-I-FLOOR , 24oc ,
Exterior, 48"(c) x 96",100 pcs. (Note "square edge" or
"tongue-and-groove" as desired.
(c) Most tongue-and-groove panels are manufactured with a
47-1/2-inch net face width, although manufacturing practices vary. Check with your
supplier. |
