Estrutura de aço para edifícios industriais: vãos, alturas e pontes rolantes

KXD Steel Technical & Project Team | Engineering & Project Delivery, Qingdao KXD Steel Structure Co., Ltd. | Published: August 20, 2026

An industrial steel building is defined by four numbers: clear span 20–80 m, building length 30–300 m, eave height 6–18 m, and bay spacing 6–9 m. Overhead crane capacity, up to 50 t, sits underneath all four. Choosing the wrong combination is the most expensive mistake at design stage.

Parameters below reflect KXD’s published product-page specifications as of August 2026. Design codes and local load requirements change; confirm site-specific values with an engineer before finalising a layout.

The Four Numbers That Define the Building

Most technical material on this topic explains how portal frames behave structurally. Fewer sources connect the parameter ranges to what a buyer is actually deciding, which is what fits inside the building and what it will cost to run.

The four dimensional parameters are not independent. Increasing span raises the frame depth, which raises the eave height needed for the same clear working height. Adding crane capacity forces column sections up, which changes what bay spacing is economical. A layout that fixes all four at once, without checking the interactions, usually gets re-priced after the first engineering review.

Span Ranges Matched to Production Layouts

Clear span is the parameter buyers most often specify by habit rather than by requirement. The table below works the other way round, starting from the layout.

The last row deserves a caution. Column-free width above 65 m is sometimes specified as a comfort margin rather than a genuine constraint. Where an internal column line is tolerable, splitting an 80 m span into two 40 m spans lowers frame weight substantially, and the saved tonnage usually exceeds the cost of the extra foundation line.

Compared with the fixed-span catalogue packages common in this product category, a custom-engineered frame lets the span follow the equipment layout rather than the other way round. That matters most in the 25–50 m band, where a 3 m mismatch between catalogue span and required aisle width can force an entire line to be rearranged.

Working Out Eave Height from the Crane Down

Eave height is derived, not chosen. When a building carries an overhead crane, the sequence runs upward from the load:

• Establish the required hook height. The highest point the load must clear, plus the sling or lifting-beam length above it.
• Add crane clearance. Distance from hook at its top position to the underside of the crane girder, per the crane supplier’s data.
• Add the crane bridge and end carriage depth. This comes from the crane manufacturer, not the building fabricator, and it varies considerably between capacities.
• Add the runway girder depth and rail height. The runway girder spans between building columns, so its depth is a function of bay spacing as well as crane load.
• Add clearance to the underside of the roof frame. The frame haunch or truss bottom chord sits above this, and its depth grows with span.

Worked as an example: a 10 t crane needing 8 m hook height, with roughly 1.5 m of crane clearance and bridge depth, a 0.9 m runway girder plus rail, and 0.6 m of frame clearance, arrives near 11 m at the crane rail and pushes eave height toward 12–13 m depending on frame depth. Substitute your own crane data before using this arithmetic.

Buildings without cranes invert the logic. There, eave height follows racking height, forklift mast extension at full lift, and sprinkler clearance, and 6–9 m covers most cases.

Bay Spacing: 6 m or 9 m

Bay spacing is where a small decision compounds across the whole building. For a 120 m long building:

Neither column wins on weight alone. What tips the decision is usually the crane and the wall openings. Heavy cranes favour 6 m bays because runway girder depth grows fast with span. Buildings with many loading docks or wide roller doors favour 9 m bays, because a column landing in the middle of a required opening is a problem no amount of steel optimisation solves.

What Crane Capacity Actually Changes

A frequent misconception, and one that shows up in enquiries regularly: crane capacity is treated as a runway beam question, as if the rest of the building is unaffected.

It is not. Adding crane load changes the column section, the base fixity, the foundation moment, and often the bracing layout. Retrofitting a 20 t crane into a frame that was designed without crane provision generally means strengthening columns and rebuilding foundations, which is comparable in cost to the original steelwork.

If crane installation is planned for a later phase, say so at design stage. Designing the frame for a future crane and installing it later costs a fraction of retrofitting into a frame that never anticipated it. This is the single most useful thing a buyer can tell an engineer early.

Industrial Steel Building: Published Specification

On price: KXD does not publish a price range on the Industrial Steel Building product page, so this configuration is quotation-only. For directional reference, the Custom Steel Structure Building category is published at USD 40–100/m², but that is a different product listing and should not be treated as a quote for an industrial building with crane loading. A firm figure requires span, length, eave height, crane data and the governing design code.

The published envelope has real edges, and they matter more than the marketing case for steel.

Below 600 m² the MOQ makes this product unavailable, and below roughly 20 m span the economics favour lighter shed systems anyway. At the other end, buildings approaching the 300 m length limit typically need thermal expansion joints, which split the structure into independent blocks and add connection detailing that shorter buildings avoid. Budgeting a 280 m building as though it were two 140 m buildings priced per square metre understates it.

Wind resistance is listed at up to 50 m/s, but that ceiling is a design capability, not a default. A site in a cyclone-exposed region needs its own load case, and the resulting bracing and cladding fixings will not match a sheltered inland site of the same dimensions.

There is also a lead-time consequence buyers underestimate. Heavier crane structures involve more welded connection detailing and more inspection scope than a plain portal frame, so the fabrication schedule for a 50 t crane building is not the same as for an identical envelope without one.

Codes, Loads and What Certification Covers

Structural design here follows the destination code rather than a single international standard. GB, ASTM and BS references appear across KXD’s industrial product lines, and the applicable one is set by the project location and the local approval authority.

Certification operates on a separate track. The European Commission states that CE marking for construction products indicates conformity with declared performance assessed under a harmonised European standard or a European Technical Assessment, with EN 1090 referenced specifically for structural products. For an industrial building destined for the EU, EN 1090 factory production control is a precondition of supply, not a value-add.

ISO defines ISO 9001 as its quality management system standard, ISO 14001 as its environmental management system standard, and ISO 45001 as its occupational health and safety management system standard. These describe how a supplier operates. They say nothing about whether a 60 m span frame has been designed correctly for your crane, which is why the design code question and the certification question have to be asked separately.

Third-party inspection through SGS, Bureau Veritas or Intertek is available on request as a scoped service. Specify it in the enquiry if it is required.

Perguntas frequentes

Q: What is the maximum span for an industrial steel building?

A: 80 m clear span is the published maximum for this product. Beyond about 65 m, trussed frames generally replace solid-web portal frames, and steel weight per square metre rises noticeably.

Q: What eave height do I need for a 10 t overhead crane?

A: It depends on required hook height. Working upward from hook height through crane clearance, bridge depth, runway girder and roof frame clearance typically lands in the 12–14 m region for an 8 m hook height, but the crane supplier’s dimensional data governs. Published eave height range for this product is 6–18 m.

Q: Is 6 m or 9 m bay spacing better?

A: Neither is universally better. Heavy crane loads favour 6 m because runway girder depth grows with span. Buildings needing wide wall openings for docks or roller doors favour 9 m. Total steel weight tends to be similar.

Q: Can a crane be added after the building is finished?

A: Only if the frame was designed for it. Retrofitting into a frame with no crane provision usually requires column strengthening and foundation work. Declaring a future crane at design stage costs very little by comparison.

Q: How much does an industrial steel building cost?

A: There is no published price range for this specific product configuration; it is quotation-only. The variables that determine it are span, eave height, crane capacity, cladding specification and the governing design code.

Q: What is the minimum project size?

A: 600 m². Smaller industrial buildings fall outside this product line.

Q: How long can the building be?

A: 30–300 m is the published range. Longer buildings commonly require thermal expansion joints, which should be discussed at layout stage rather than discovered during detailing.

Before You Send Dimensions to an Engineer

The layout information that produces an accurate design, in the order it is usually needed: equipment footprint and required aisle widths, crane capacity and hook height, wall opening positions and sizes, site wind and snow data, and the code the local authority will approve against.

One question this article deliberately leaves open: whether a mezzanine floor is worth adding rather than extending the footprint. That trade-off depends on load class, fire separation requirements and local floor-area regulations, and it deserves its own analysis rather than a paragraph here.

About the author: The KXD Steel Technical & Project Team works on design, detailing, fabrication and delivery of prefabricated steel structures for industrial, commercial, logistics, agricultural and infrastructure applications, with steel-structure expertise dating to 1997 and project experience across more than 80 countries and regions. In-house engineering tools include Tekla, PKPM and 3D3S.