Like the purlin sleeved system, Z-purlins used in a side rail
application cater for spanning multiple bays or supporting
heavier loads with the incorporation of a sleeve, fixing the
purlins to the cleat. This significantly increases the loading
capability of the system.
here to view load span data of all systems for various
The following fixing systems apply mostly to sleeved purlins
used in multi-bay or heavy end bay applications.
Sleeve Arrangement (Double Span)
Using a staggered
sleeve arrangement increases the loading capabilities of the
system in comparison to the butted system, whilst still
offering a cost effective solution. In the diagram below you
can see the staggered arrangement of sleeves. Care must be
taken during installation to maintain erection sequence.
system, sleeves at the ends of the span are positioned at
every support. Internal bays have sleeves staggered on
alternate supports and utilise lower gauge (thinner) sections
and sleeves. The effect of staggering reduces the number of
sleeves required and therefore the number of installation
components, whilst still retaining most of the strength of a
sleeved single span system.
Below you will
find examples of Z-purlins used in different applications.
two Z-purlins at the apex of the roof on which roofing sheets
on either side of the apex are placed, flush to the apex. An
external ridge is fixed on top of the sheets to prevent water
horizontal roof Z-purlin at the gable end of the building