Load-Bearing Basics for Non-Engineers
01Dead load vs. live load
Dead load is the permanent weight of the structure itself and anything fixed to it — roof sheeting, ceilings, fixed equipment. Live load is variable — people, movable equipment, stored goods. Structures are designed for the combined worst-case, not just the everyday load.
02Wind load matters more than most people expect
For large clear-span roof structures, wind uplift is often the governing design case, not the weight sitting on the roof. This is why regional wind zone data feeds directly into purlin spacing and frame sizing on agricultural and industrial buildings.
03Why 'it looks strong enough' isn't a design method
Section sizing is calculated, not eyeballed — a beam that looks oversized for a light load may still be the correct size once wind uplift, deflection limits, and connection capacity are factored in. This is why we always recommend engineering sign-off for anything load-bearing, even when a client is confident about the load.
04What this means for your quote
When you request a quote for a structural item, the more detail you can give about intended use, loading, and location, the more accurate the first quote will be — and the less likely a redesign is needed once engineering review happens.
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