Can I Use the Structural Drawings to Take Final Beam Lengths for Fabrication?

No. Structural drawings are not fabrication drawings and must not be used to derive final beam lengths or setting-out dimensions.

Every PorthouseDean structural drawing carries a clear marking: “NOT TO SCALE. INDICATIVE ONLY. DO NOT TAKE FINAL DIMENSIONS FROM THIS DOCUMENT.”

What Structural Drawings Are For

Structural drawings communicate design intent. They show:

– Which beam sections are required and where
– The structural layout and how elements relate to each other
– Connection types and principles
– Load paths and support conditions
– Steel grades and specifications

They are not produced to fabrication tolerances, do not account for site-specific construction variations, and may not reflect small dimensional changes that occurred during construction.

Where Final Beam Lengths Should Come From

Final beam lengths and setting-out dimensions should be taken from:

1. The architectural drawings — which are the design reference for all dimensional information
2. Site measurement — confirmed by the builder or fabricator prior to ordering steel

Many fabrication problems (beams too short, beams that miss their padstones, connection plates that don’t line up) arise directly from fabricators scaling dimensions off structural drawings rather than measuring from site.

Who Is Responsible?

The fabricator is responsible for confirming all final dimensions before manufacturing. This is standard industry practice and is explicitly required by the National Structural Steelwork Specification (NSSS), to which all steel fabrication on PorthouseDean projects must conform.

PorthouseDean does not provide fabrication lengths as part of the standard structural design service.

What About After Installation?

If a beam has been fabricated and is the wrong length, see the article on beam cut too short. If you need a formal fabrication-length computation as part of the design, this can be requested as an additional service — raise it with PorthouseDean at the start of your project.

Contact PorthouseDean if you have questions about the scope of your structural package.