Steel warehouses and workshops: how the frame goes up

In steel building the first question is not "how many square metres" but "how many metres of clear span". The distance to be crossed without columns sets every other dimension in the frame.

Span decides everything

A 12 metre span and a 40 metre span are not the same building. As the span grows the truss gets deeper, sections get heavier and foundation loads rise. If a forklift must turn inside, or a crane must run, the column grid follows from that; columns cannot be removed later.

Roof trusses

The truss carries roof load to the columns. Snow, wind and the weight of the covering are summed and taken through it. Whether sandwich panel or trapezoidal sheet is used is an input to that calculation — mineral wool panel is markedly heavier than polyurethane and grows the truss.

Purlin spacing

Purlins sit between trusses and carry the covering. Their spacing follows the span capacity of the covering; thicker panels allow wider spacing. Leaving purlins too far apart means a roof that flexes underfoot.

Fabrication and erection

The advantage of steel is that parts are made in the shop, not on site: cutting, holes and welding happen in controlled conditions and only assembly remains on site. That shortens the programme and reduces weather dependency.

We fabricate bespoke structural steel in our own workshop and erect it with our own crew; we do not subcontract. The people who do the work are the people who answer for it.

Column positions are cheap on paper and expensive after the concrete. Discuss span and internal use at the very start.

Corrosion

A frame that stays enclosed can be built in painted black section. In open structures exposed to sea air and in damp production halls, galvanised is chosen; on the coast that decision sets the life of the building.

Tell us the span, the use of the building and your preferred roof covering, and we can measure on site and set out the programme with you.