Scope & assumptions
Code-neutral tributary-width conversion followed by a simply supported UDL beam demand calculation.
METRIC REPUBLIC ENGINEERING · PRELIMINARY
Purlin Tributary Load Calculator
Convert roof area loads and purlin spacing into design line load, reactions and simply-supported moment.
PurlinTributary loadRoofing
Calculation basis
gline = gk·btrib; qline = qk·btrib; qd = γGgline + γQqline; M = qdL²/8; R = qdL/2.
Important engineering note: Member resistance, continuity, uplift load combinations, bracing, restraint, local effects and profile/manufacturer data are not checked.
Reference basis
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Frequently asked questions
Is this a complete code design?
No. It is a transparent preliminary calculation. Code-specific limits, detailing, stability and project conditions must be verified independently.
Can I use the result for construction?
Use the result as a screening or checking aid only. Final design and construction documents should be verified by a qualified professional where required.
Why are some resistance factors entered by the user?
Many design standards contain member-, material-, product- or project-specific values. Metric Republic keeps these visible and user-controlled instead of hiding assumptions.