18
d
c
b
a
e
5
MOUNTING METHOD 4: PURLINS
NOTE: Purlin brackets and hardware are available from S&P upon request and not included standard.
5.9 Selecting Proper Angle Irons
Select the proper angle irons based on the requirements stated under section 5.3.
5.10
Pre-Drill Purlins
Drill four 9/16” (1.4 cm) diameter holes centered vertically along the purlin spaced apart 4.5” (11.4 cm)
horizontally and 1.5” (3.8 cm) vertically. These holes should match up perfectly with those of the purlin bracket and
back plate.
5.11 Attach Brackets and Backing Plates
Purlin mounting brackets and backing plates should be attached using the provided 1/2” grade 5 bolts, washers,
and nylock nuts. A washer should be placed on both sides of the plate for each bolt.
5.12 Pre-Drill Angle Iron Brackets Holes
Your angle iron should be cut to allow 1/2” (1.27 cm) clearance between the end of the angle iron and the purlin
you are mounting to. Drill one 9/16” (1.4 cm) diameter hole centered vertically exactly 1” (2.54 cm) from the edge
on both ends of the vertical wall of the angle iron. Drill a second hole exactly 3” (7.6 cm) inward from the first hole
on both ends. Repeat for the second angle iron. These holes will be used to secure the angle iron to the purlin bracket
with the provided hardware.
5.13 Pre-Drill Angle Iron Fan Mounting Holes
Measure the distance between the mounting points that each angle iron will span. Drill two 9/16” (1.4 cm) diameter
holes centered on the bottom wall of each angle iron. The two holes should be spaced 5.5” (13.9 cm) apart to best
match those of the upper yolk. These holes will attach the upper yolk to the angle iron.
