Details about introduction of purlins used in industrial structures.

1. PURLINS
Prepared by
DEEPA.B
ASSISTANT PROFESSOR/CIVIL
KCET,Madurai

2. • In steel construction, the term purlin typically
refers to roof framing members that span
parallel to the building eave, and support
the roof decking or sheeting.
• The purlins are in turn supported by rafters or
walls.
• It is a member which rest between roof truss
and supports the sheeting.

3. • The purlins are spaced on main rafter of
trusses such that the sheets overlap on them.
• A.C – sheet – overlap – atleast 150mm
• Spacing of purlins – 1.35m to 1.40m (A.C sheet
of length 1.65m)

18. Contd.,

19. Commonly used purlins:
I – sections
Channels
Angles
Cold formed C or Z sections

20. CLEAT ANGLE
A short length of angle iron used as a
bracket. Expand.
Also called seat angle.