Installation Guide

ENGINEERED WOOD CONSTRUCTION GUIDE
■
FORM NO. E30V
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© 2011 APA – THE ENGINEERED WOOD ASSOCIATION
■
WWW.APAWOOD.ORG
64
Roof Construction
TABLE 33
RECOMMENDED ROOF LOADS (PSF) FOR APA RATED SHEATHING WITH
STRENGTH AXIS PARALLEL TO SUPPORTS
(a)(b)
(OSB and 5-ply/5-layer plywood panels unless otherwise noted)
Panel Grade
Panel
Performance
Category Span Rating
Maximum
Span
(in.)
Load at Maximum Span
Live Total
APA STRUCTURAL I
RATED SHEATHING
7/16
15/32, 1/2
19/32, 5/8
23/32, 3/4
24/16
32/16
40/20
48/24
24
(c)
24
24
24
15
30
(d)
70
(e)
105
(f)
25
40
(d)
80
(e)
115
(f)
APA RATED
SHEATHING
7/16
15/32, 1/2
19/32, 5/8
23/32, 3/4
24/16
32/16
40/20
48/24
16
24
(c)
24
24
35
15
(g)
40
(h)
70
(e)
45
25
(g)
50
(h)
80
(e)
(a) For guaranteed or warranted roofs, contact membrane
manufacturer for acceptable deck.
(b) Provide edge support.
(c) Solid blocking recommended at panel ends for 24-inch span.
(d) For 4-ply plywood, reduce load by 10 psf.
(e) For 4-ply plywood, reduce load by 30 psf.
(f) For 4-ply plywood, reduce load by 45 psf.
(g) For 4-ply plywood, reduce load by 5 psf.
(h) For 4-ply plywood, reduce load by 15 psf.
TABLE 34
STIFFENER LOAD-SPAN TABLES FOR PREFRAMED APA PANEL ROOF DECKS
Douglas fir-Larch Allowable Roof Live Load (psf)
(a)
Center-
to-Center
Purlin
Spacing
(b)
(ft)
Stiffener
Size and
Spacing
(in.)
Select Structural No. 1 & Better No. 1 No. 2
Defl.
(c)
Strength
(d)
Defl.
(c)
Strength
(d)
Defl.
(c)
Strength
(d)
Defl.
(c)
Strength
(d)
1.15 1.25 1.15 1.25 1.15 1.25 1.15 1.25
8
2 x 4@16
2 x 4@ 24
2 x 6@16
2 x 6@24
2 x 6@32
37
25
144
96
72
67
41
154
99
61
73
46
168
109
68
35
23
136
91
68
51
31
121
78
47
57
34
133
85
52
33
22
129
86
64
41
24
99
63
38
46
27
109
69
42
31
21
121
81
61
36
21
88
56
33
40
23
97
61
37
Southern Pine Allowable Roof Live Load (psf)
(a)
Center-
to-Center
Purlin
Spacing
(b)
(ft)
Stiffener
Size and
Spacing
(in.)
Select Structural No. 1 Dense No. 1 No. 2
Defl.
(c)
Strength
(d)
Defl.
(c)
Strength
(d)
Defl.
(c)
Strength
(d)
Defl.
(c)
Strength
(d)
1.15 1.25 1.15 1.25 1.15 1.25 1.15 1.25
8
2 x 4@16
2 x 4@24
2 x 6@16
2 x6@24
2 x 6@32
35
23
136
91
68
87
55
205
133
83
96
60
223
146
91
35
23
136
91
68
58
35
137
88
54
64
39
150
97
60
33
22
129
86
64
53
32
129
83
50
59
36
141
91
56
31
21
121
81
61
41
24
95
60
36
46
27
104
66
40
(a) Final allowable load is the lesser of the loads as determined by
deflection and stress.
(b) Actual span of stiffeners taken as 3-1/2 inches less than
center-to-center spacing of purlins.
(c) Deflection limitations: Span/240 under live load only; Span/180
under total load, assuming a dead load of 10 psf.
(d) Loads limited by stress are based on two conditions of duration
of load: two months, such as for snow (1.15); and seven days
(1.25); includes effects of 10 psf dead load.