Reviewing a subcontractor's shop drawings before you forward them
The steel stair package for a three-storey youth centre arrives at 16:10 with the fabricator's note: "Please forward today to hold our shop slot." It is 14 sheets. Stamping and forwarding it would take five minutes.
Before you forward shop drawings, check that the package is complete and meets the specification, then check what only the general contractor can see — dimensions against the current drawings and the site, and connections to other trades' work — and record the review with every deviation listed. The fabricator knows its product and the consultant checks the design, but neither sees the slab edge as poured or the wall the handrail bolts to. The US federal clause for fixed-price construction contracts, for example, requires the contractor to coordinate and review shop drawings, show its approval on them and describe any variations in writing, separately; the government's approval does not relieve it of errors or omissions.
- Check the package is complete first: every item the section asks for — drawings, calculations, product data, finishes, certificates. Send an incomplete one back the same day with a list.
- Check dimensions against the current revision and the site: sizes, elevations, grid locations, the revisions the detailer worked from, and field measurements of built work.
- Check every interface: bearings, embeds, anchors, openings, backing and clearances. Send the pages that touch other trades to those foremen.
- Check the specification line by line: materials, grades, finishes, design and performance requirements, tests and certificates.
- Mark the drawings, not an email: cloud each comment on the sheet, and list deviations separately in the transmittal.
- Return or forward: send back what needs redrawing, and forward only a package you would build from, stamped with who reviewed it, when and what was checked.
Common mistakes
- Stamping at 16:30 because the fabricator is waiting.
- Checking against the tender set in your binder.
- Reviewing a trade's own scope but not what it bears on or bolts to.
- Leaving deviations for the consultant to find.
Checklist
Before you stamp and forward
- Every required item in the package
- Drawn to the current revision
- Dimensions checked against drawings and site
- Interfaces read by the trades they touch
- Specification checked, deviations listed
- Review recorded: who, when and what
Check your understanding
The fabricator says the architect will catch any errors, so your review only slows things down. How do you answer?
