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Four structural systems are available, the Sleeved System, Double-Span Sleeved System, Heavy End-Bay System and the Butted System. These systems allow for a flexible and efficient range of solutions to roofing supports for a wide variety of cladding types, the major features of which are outlined below.
Sleeved single-span system
This is the traditional system of single bay-length
sections with sleeves at all penultimate supports and at
alternative internal supports. The system may be used
with all types of cladding and roof pitches, within the
limitations given in this manual. Minimum number of
spans is 2 and the maximum span is 12.5m. |
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Sleeved double-span system
Sleeves are provided at all penultimate supports and are
staggered at internal bays. The advantage is a reduced
number of erection components when compared with
the Sleeved System. Note that maximum section length
is restricted to 15m for transport and handling reasons.
Consideration should be given to handling and erection
sequence when utilising the double-span sections.
Minimum number of spans is 4 and the maximum span
is 7.5m. |
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Heavy end single-span system
This is a highly efficient sleeved-system, with sleeves at
all supports thus allowing a form of continuous beam
design. Inner bay sections and sleeves are thinner than at
the end bay thus allowing an economic solution for long
buildings. Sleeves at penultimate supports are of the
same thickness as the outer bay purlin section. Minimum
number of spans is 4 and maximum span is 12.5m. |
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Heavy end-bay double-span system
Sleeves are provided at all penultimate supports and are
staggered at internal bays. The advantage is a reduced
number of erection components. Inner bay sections and
sleeves are thinner than at the end bay thus allowing an
economic solution for long buildings. Sleeves at
penultimate supports are of the same thickness as the
outer bay purlin section. Minimum number of spans is 4
and maximum span is 12.5m. |
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Sleeved purlin system
Single/Double span lengths
This system may be used with restraining or non-restraining
cladding, and may also be used to support tiled roof systems.
The system may require to be used in conjunction with sag systems
as identified for various conditions (see design guidance
PDF). Consideration should be given to handling and erection
sequence when utilising the double-span section. |
DOUBLE SPAN CONNECTION
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SLEEVED CONNECTION
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Butted single-span system
The system is required for buildings of a single span
length and is efficient for short spans or light loadings.
Butted purlins are also useful for frames which have
large clear spans and where large frame deflections may
be harmful to continuous purlin systems. Butted purlins
can be used over supports or within the depth of the
supporting section. Maximum span is 11.4m. |
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Butted purlin system
This system is useful for single-span conditions, either
over-supports or flush with supports. The system is also
economical for small bays or light loadings, where
sleeves are not necessary. |
BUTTED CONNECTION
with inset cleat for flush construction
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BUTTED CONNECTION
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Design guidance
Design guidance for the Steadmans Zed Purlin systems
and their use with sag bar system, roof angle brace
system, monopitch roofs, steep pitch roofs, shallow pitch
roofs, long roof slopes, curved roofs, tiled roofs and
cantilever purlins is contained in a PDF. Download the
PDF by clicking on the link to the right. |
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