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
Fastener spacing
Support Spacing , ft 4.0 4.5 5.0 5.5 6.0 6.5 7.0 8.0
36 / 11 |
6 " |
78 |
69 |
63 |
59 |
53 |
50 |
46 |
40 |
36 / 9 |
6 " |
61 |
56 |
50 |
45 |
43 |
39 |
36 |
33 |
36 / 7 |
6 " |
53 |
48 |
43 |
39 |
37 |
34 |
32 |
28 |
36 / 5 |
6-12-12-6 |
37 |
33 |
30 |
28 |
26 |
24 |
23 |
20 |
36 / 4 |
12 " |
29 |
26 |
22 |
22 |
21 |
19 |
18 |
16 |
36 / 3 |
18 " |
21 |
19 |
17 |
16 |
15 |
14 |
13 |
12 |
30 / 6 |
6 " |
53 |
48 |
43 |
39 |
37 |
34 |
32 |
28 |
30 / 4 |
6-18-6 |
34 |
30 |
28 |
26 |
24 |
22 |
21 |
19 |
30 / 3 |
12-18 |
24 |
22 |
20 |
19 |
17 |
16 |
15 |
14 |
24 / 5 |
6 " |
53 |
48 |
43 |
39 |
37 |
34 |
32 |
28 |
24 / 3 |
6 " |
29 |
26 |
22 |
22 |
21 |
19 |
18 |
16 |
24 / 4 |
8 " |
41 |
37 |
34 |
31 |
29 |
27 |
25 |
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
Table 5 - Common steel deck types and dimensions 1 , 3
Deck Type
B
BI
N
F
Composite Deck
Common Thickness
16-24 GA
16-24 GA
16-22 GA
18-22 GA
16-22 GA
1 "
2.5 "
1.75 "
2.75 "
1.75 "
1.75 "
0.5 "
6 "
Standard Dimensions
6 "
8 "
6 "
12 " 7.25 "
4.75 "
36 "
1.75 "
36 "
24 "
36 "
36 "
3 "
1.5 "
2.5 " 3.5 "
1.5 "
0.75 " 0.75 "
1.5 " 3 "
Sidelap fastener estimation
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 6 - Steel deck gauge ( GA ) inch and millimeter equivalent 2 , 3
Gauge ( GA )
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 .
Form Deck |
24-28 GA |
1.5 " 2.5 "
1 "
|
30 " |
9 / 16 " |
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