Fabrication Drawings: Why Your Fabricator Must Send Them to Us Before Starting

PorthouseDean’s structural drawings specify the beams, sections, connections, and dimensional constraints your project requires. But there is a critical step between those drawings and steel being cut in the workshop: the fabricator’s own shop drawings.

These must be submitted to PorthouseDean for review and approval before any fabrication commences.

What Fabrication Drawings Are

When a fabricator receives structural drawings, they produce their own detailed workshop drawings — sometimes called shop drawings or fabrication drawings. These show:

– Exact cut lengths and section designations
– Hole positions, end-plate weld dimensions, and fin-plate locations
– Splice positions and connection details
– Any shop-welded components (cap plates, base plates, stiffener plates)
– Corrosion protection specification

These drawings translate the engineer’s design intent into actionable workshop instructions.

Why They Must Be Reviewed Before Fabrication

Fabrication drawings occasionally contain errors or misinterpretations of the structural design. Common issues include:

– Incorrect section designation (e.g. 203×203×60 UC instead of 203×203×71 UC)
– End plate or fin plate positioned at the wrong level
– Missing stiffeners or cap plates
– Wrong hole positions or spacings
– Incorrect material grade assumed

Once steel has been cut and holes drilled, corrections are expensive and time-consuming. In the worst case, a fabricated beam is unusable. The review step exists to catch these errors before material is wasted.

What Happens During Review

PorthouseDean will check the fabrication drawings against the structural design. We are looking to confirm that:

1. Section references match the specification
2. Connection details have been interpreted correctly
3. Plate sizes and thicknesses are sufficient
4. Hole patterns and bolt grades match the design intent
5. Any special instructions (e.g. specific weld sizes, galvanising, pre-drilled holes for services) are captured

We will either approve the drawings or return them with comments. This is not a structural redesign — it is a verification step.

Your Role in This Process

As the client, instruct your fabricator at the point of appointment that fabrication drawings must be forwarded to PorthouseDean for approval before any cutting begins. This is a standard industry requirement, and experienced fabricators will expect it.

Do not allow your fabricator to proceed on the assumption that the structural drawings are sufficient for fabrication without this review. They are not.

Contact us if you have a time-sensitive fabrication programme and need to discuss the review timeline.