The First Step: Stop, Document, Notify
When a field condition doesn't match a drawing, the correct first step is not to improvise a fix — it is to stop the affected work, photograph the existing condition, and notify the GC and detailer immediately. The notification should include: the location (gridline, floor, piece mark), a description of the discrepancy, and a photograph. Do not proceed with erection, modification, or alternative assembly until engineering guidance is received.
Typical Field Discrepancy Types
- Foundation anchor bolts out of tolerance — position, projection, or diameter doesn't match anchor bolt drawing
- Existing conditions in renovation work differ from contract documents — beam sizes, slab thicknesses, or column locations don't match the survey
- Member arrives from the shop with dimensions that don't match the field assembly — a length error or hole pattern error
- Adjacent trade installation conflicts with the steel — a duct or pipe was installed in a location that the steel now occupies
- Foundation elevation out of tolerance — base plates cannot achieve plumb without shimming beyond what the contract documents allow
Who Provides Engineering Guidance
Field discrepancies that affect structural adequacy require EOR input — not the detailer, not the GC superintendent, and not the ironworker foreman. The detailer's role is to document the discrepancy clearly and communicate it to the EOR through the GC's RFI process, with a proposed resolution if one is technically defensible. The EOR responds with engineering direction. Only after that direction is received — and documented in writing — should field work resume.
The Field RFI — Different from a Design RFI
A field RFI is issued under time pressure that a design-phase RFI usually is not. The crane may be standing; the erection crew may be on site. A field RFI should be marked 'URGENT' with a specific required response time — typically 24–48 hours rather than the 10–14 business days typical for design-phase reviews. It should include: a photograph of the condition, the piece mark and gridline, a clear description of the discrepancy, and a proposed resolution. Sending a well-prepared field RFI with a proposed resolution dramatically accelerates the EOR's response time compared to an open-ended 'we have a problem, please advise.'
Field Modification Approvals and Documentation
Any field modification made to resolve a discrepancy must be documented as formally as the original shop drawing change. An engineering release from the EOR — typically a signed, dated letter, email, or marked-up sketch — is required before the modification is made. After the modification is complete, the detailer must update the model and issue revised drawings reflecting the as-modified condition. Field fixes that are not documented in the drawing set create as-built discrepancies that become problems during future renovation or structural assessment.
- EOR approval in writing before any structural modification
- Field sketch or photograph documenting the pre-modification condition
- Revised drawing issued with 'Field Modified' notation and revision description
- As-built model updated to reflect the modification
- Transmittal sent to fabricator PM documenting the field modification and drawing revision
Preventing Field Discrepancies Through Pre-Erection Drawing Review
The most effective intervention for preventing field fit-up problems is a pre-erection drawing review — a session where the erection superintendent reviews the shop drawings and erection drawings with the detailing PM before the crane mobilizes. This review catches clearance issues, connection sequences, and member orientation questions while they can be resolved at a desk, not under a loaded crane. On complex projects, Tectonix project managers schedule a pre-erection call with the erection crew to walk through the first week's picks, confirm connection sequencing, and flag any members that require special handling. This 2-hour investment consistently prevents a full day of erection delays.