Installation Guide

Page
11
SunFrame Unirac Code-Compliant Installation Manual
R
1411 Broadway Boulevard NE
Albuquerque NM 87102-1545 USA
Step 2a: Determine the Distributed Load on the rail
based on uplift and downforce, w (plf):
Determine the Distributed Load, w (plf), by multiplying the
module dimension, B (ft), by the Total Design Load, P (psf). Use
the maximum absolute value of the three downforce cases and
the Uplift Case. We assume each module is supported
by one rail.
w = PB
w = Distributed Load (pounds per linear foot, plf)
B = Module Dimension Perpendicular to Rails (ft., see Figure 3)
P = Total Design Pressure (pounds per square foot, psf)
Step 2b: Determine the Distributed Load on the rail
based on side load, w (plf):
Determine the Distributed Load w (plf), by multiplying the
module width B (ft) by the Total Design Load P (side)
w = PB
w = Distributed Load (pounds per linear foot, plf)
B = Module Dimension Perpendicular to Rails (ft)
P = Total Design Pressure for side load (pounds per square foot, psf)
Step 3: Determine Rail Span/ L-Foot Spacing:
Using the distributed load, w, from Part II, Step 2, look up the
allowable spans, L, for SunFrame.
There are two tables, Table 8a for uplift and downforce and
Table 8b for side load. Look up the allowable span for uplift/
downforce from Table 8a and side load from Table 8b. Span
for the system will be the lower of the 2 appropriate values
from Tables 8a and 8b.
Table 7. ASCE 7 ASD Load Combinations
Note: Table to be filled out or attached for evaluation.
Description Variable Downforce
Case 1
Downforce
Case 2
Downforce
Case 3
Uplift Side Units
Dead Load D 1.0 x D ______
1.0 x S ______
1.0 x D ______
1.0 x P
net
____
1.0 x D _______
0.75 x S _______
0.75 x P
net
____
0.6 x D _______
1.0 x P
net
______
sin(roof angle) x D
__________
sin(roof angle) x S
__________
psf
Snow Load S psf
Design Wind
Load
P
net
psf
Total Design
Load P
P Sum of above two
numbers ______
Sum of above two
numbers ______
Sum of above 3
numbers ______
Sum above two
numbers* ______
Sum above two
numbers ______
psf
Table 8a. L-Foot SunFrame Series Rail Span (uplift and downforce)
20 25 30 40 50 60 80 100 120 140 160 180 200 220240 260280 300
2SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSF
2.5SFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSFSF
3SFSFSFSFSFSFSFSFSFSFSFSFSFSFSF
3.5SFSFSFSFSFSFSFSFSFSFSFSFSFSF
4SFSFSFSFSFSFSFSFSFSFSFSF
4.5SFSFSFSFSFSFSFSFSFSFSF
5SFSFSFSFSFSFSFSFSFSF
5.5SFSFSFSFSFSFSFSFSFSF
6SFSFSFSFSFSFSFSFSF
6.5SFSFSFSFSFSFSFSF
7SFSFSFSFSFSFSFSF
7.5SFSFSFSFSFSFSFSF
8SFSFSFSFSFSFSF
8.5SFSFSFSFSFSFSF
9SFSFSFSFSFSF
9.5SFSFSFSFSFSF
10 SF SF SF SF SF
10.5 SF SF SF SF
11 SF SF SF SF
11.5 SF SF SF
12 SF SF SF
w = Distributed Load (plf)
Span
(ft)
Table 8a. L-Foot SunFrame Series Rail Span (uplift and downforce)