Steel Deck Fastening Systems
1.1 Steel Deck Fastener Design and Selection
1.1.6 Fastener Quantity Estimation
Table 4 - Frame fasteners per square of roof 1,2,3
Fastener
Pattern
36/11
36/9
36/7
36/5
36/4
36/3
30/6
30/4
30/3
24/5
24/3
24/4
Fastener
spacing
4.0
6"
78
6"
61
6"
53
6-12-12-6
37
12"
29
18"
21
6"
53
6-18-6
34
12-18
24
6"
53
6"
29
8"
41
4.5
69
56
48
33
26
19
48
30
22
48
26
37
5.0
63
50
43
30
22
17
43
28
20
43
22
34
Support Spacing, ft
5.5
6.0
59
53
45
43
39
37
28
26
22
21
16
15
39
37
26
24
19
17
39
37
22
21
31
29
Sidelap fastener estimation
6.5
50
39
34
24
19
14
34
22
16
34
19
27
7.0
46
36
32
23
18
13
32
21
15
32
18
25
8.0
40
33
28
20
16
12
28
19
14
28
16
22
1 Hilti Profis DF Diaphragm software also estimates fastener quantities.
2 Estimated quantities are for one square of decking. A square of roof decking is an area of 100 ft 2 .
No provision is made for waste. Perimeter fastening spacing is based on 12" on-center assumption.
3 For interlocking sidelaps, add 15% to quantities in table.
1.1.7 Common Steel Deck Dimensions
To estimate the number of sidelap screws
on a steel roof or floor deck project,
multiply the total deck area in square
feet times the number of required stitch
screws per span and then divide by
the sheet width times the joist spacing
(both in feet). A 5% contingency is also
recommended for waste and loss.
Example:
Total area: . . . . . . . . . 50,000 square
feet
Sheet width:. . . . . . . . 36" = 3 ft
Joist spacing:. . . . . . . 5 ft
No. of sidelap fasteners per span: 5
# of screws needed =
50,000 ft 2
x 5 x 1.05 = 17,500
3 ft x 5 ft
Table 5 - Common steel deck types and dimensions 1,3
Deck
Type
Common
Thickness
Table 6 - Steel deck gauge (GA)
inch and millimeter equivalent 2,3
Standard
Dimensions
6"
2.5"
B
16-24 GA
1.75"
36"
6"
16-24 GA
BI
2.5" 3.5"
1.75"
36"
8"
16-22 GA
1.75"
24"
N
2.75"
6"
1.75"
18-22 GA
0.5"
36"
12"
Composite
Deck
3"
7.25"
Nominal Sheet
Steel Thickness, t
in. (mm)
16 0.0598 (1.52)
18 0.0474 (1.21)
20 0.0358 (0.91)
22 0.0295 (0.76)
24 0.0239 (0.61)
26 0.0179 (0.45)
28 0.0149 (0.38)
1 Dimensions shown are typical. However,
the Structural Engineer should always
consult with the steel deck manufacturer
on the dimensions for the specific product
as they can vary depending on the
manufacturer.
2 Deck gauge inch equivalents taken from
SDI Diaphragm Design Manual. Millimeter
equivalents taken from CSSBI Design of
Steel Deck Diaphragms.
3 Calculations to produce diaphragm shear
tables with the deck profiles and gauges
shown are possible with Hilti Profis DF
Diaphragm software.
F
Gauge
(GA)
16-22 GA
36"
4.75"
Form Deck
24-28 GA
1.5"
1"
2.5"
30"
16 Hilti, Inc. (US) 1-800-879-8000 | www.us.hilti.com I en español 1-800-879-5000 I Hilti (Canada) Corp. 1-800-363-4458 I www.hilti.ca I PTG Decking Supplement 2014