Shop Drawings, Submittals & Field Measuring for Fabrication Release

Welcome

Hello, and welcome. This is Super Structures General Contractors — a national general contractor headquartered in Powhatan, Virginia — here to help you and your clients build something that lasts. We're glad you're with us, and we look forward to connecting with you.

Alright, Shop Drawings, Submittals & Field Measuring for Fabrication Release. Don't let the plain title fool you. Here's the part that actually matters on the job: Nothing gets cut until the shop drawings are approved and the openings are measured against control lines — fabricating from assumptions is how custom aluminum arrives the wrong size. Learn it well and you will run the one scope on the job where a wrong number costs weeks instead of hours, and never be the reason it did.

The intro course explained what a shop drawing is. This lesson is about the process around it: the package, the review, the measuring, and the release.

The submittal package and who reviews it

Glazing lives in Division 08 of the specifications — storefront, curtain wall, entrances, and glazing each have a section — with the perimeter sealants in Division 07. Each section lists the submittals the architect expects before fabrication:

• Product data for the framing system, glass, gaskets, sealants, and hardware.
• Shop drawings produced by the glazing contractor's detailer.
• Samples of finish, glass makeup, and gasket, and often a full-size corner sample.
• Engineering calculations for mullions, anchors, and glass, stamped by a licensed engineer where the specification requires delegated design.
• Test reports showing the system passed the specified air, water, and structural tests.
• Warranties, installer qualifications, and a mock-up where specified.

The architect's review stamp — no exceptions taken, make corrections noted, revise and resubmit, or rejected — confirms general conformance with design intent. It does not relieve the glazier of dimensions, quantities, or code compliance. Treat an approved set as permission to build, not as proof the numbers are right.

What a complete shop drawing set contains

Elevations with every frame and lite tagged; horizontal and vertical sections at head, sill, jamb, intermediate horizontal, vertical, corner, and every transition to adjacent work; anchor details with the loads and fastener sizes; a glass schedule with the makeup, heat treatment, coating surface, and which lites must carry a safety label; a sealant schedule with product, color, and primer; a hardware schedule; a finish schedule; and a bill of materials. The interface details matter most — where the sill meets the slab waterproofing, where the head meets the roof or parapet, and where the jamb meets masonry or panel. A missing detail gets invented in the field, and that invention is the leak.

Field measuring the openings

Measure after the rough opening is complete and before release, from the project's control lines and benchmark, not from the nearest finished surface. For each opening, record:

• Width at the head, mid-height, and sill.
• Height at both jambs and the center.
• Both diagonals to check square.
• Plumb of each jamb in both directions and level of the sill.
• Sill elevation against the benchmark, so sightlines align across the elevation.
• Depth and plane of the opening, and anything in the way — a beam flange, a conduit, a waterproofing lap.

Photograph the opening and note the substrate at each side. Frame size is the smallest measured dimension less the perimeter sealant joint on each side; a half-inch joint per side is a common minimum, and the specification or the sealant engineer may call for more. Frames are typically fabricated to a tolerance of about 1/8 inch, so an opening that varies by 3/4 inch across its height cannot be hidden by shims at the sightline. Flag it now.

Surveying slab edges for curtain wall

Curtain wall has no opening to measure; it has a slab edge and a line of anchors. Before release, survey the as-built slab edges and embeds with a total station or laser against the column grid. ACI 117 gives the concrete tolerances the slab edge was poured to, and those are larger than any curtain wall anchor can absorb without adjustment. Report every deviation to the system engineer before fabrication so the anchor brackets, shims, and mullion lengths are designed for the building that exists. Cast-in embeds are supplied by the glazier early, placed by the concrete crew, and verified by survey before the next pour.

Fabrication release and lead times

Release in stages by elevation and by material. Custom extrusion dies, anodized or painted finishes, and insulated glass each carry their own lead time, and glass cannot be ordered until frame sizes are final. The detailer issues a release for fabrication only when field dimensions are in hand or when the contract puts the opening tolerance on the GC and the dimensions are held on the drawings. Log every release by date; the enclosure schedule hangs on it.

Going Deeper (Intermediate)

Coordination is where shop drawings earn their keep. Give the mason and framer the rough opening size — frame plus joints plus shim space — in writing before they build, and confirm it against their shop drawings. Coordinate the deflection header at storefront under a steel beam so the head receptor leaves clearance for the beam to move. Ask the waterproofer how the air barrier and water-resistive barrier will lap into your sill flashing and show that lap on your detail. Issue an RFI when a detail cannot be built as drawn; never resolve it with an unreviewed field change.

Advanced / Pro-Level

Under delegated design, the engineer of record supplies the wind pressure, seismic drift, and slab deflection; the glazing contractor's engineer designs the system, anchors, and glass to those numbers and stamps the calculations. Pros keep the responsibility line clear in the contract and in the submittal. They run a submittal log tied to the schedule, know which items are long-lead, and chase the architect's review as hard as they chase the shop. They mark field changes on a set that becomes the record shop drawings at closeout.

Practice Challenge

A measure sheet for a storefront opening shows widths of 96-1/4 inches at the head, 96 at mid-height, and 95-3/4 at the sill; heights of 120 at both jambs; and diagonals that differ by 3/4 inch. What frame width goes to the shop, and what else happens? (Answer: the frame width is based on the smallest reading, 95-3/4, less the perimeter joint on each side — with a half-inch joint that is 94-3/4 — but the 3/4-inch diagonal difference means the opening is out of square beyond what shims can hide; the glazier flags it to the GC, the opening is corrected or a larger joint is agreed in writing, and nothing is released until it is resolved.)

In Practice

A detailer who releases from a measure sheet tied to the benchmark and a reviewed set of interface details sends frames that fit the day they arrive. One who releases from the architectural dimensions and a phone call from the field gets a truck of aluminum that is an inch too short for an opening the mason built to the wrong size.

Common Mistakes to Avoid

• Treating the architect's review stamp as a check of dimensions and quantities
• Measuring from the finished floor or a jamb instead of the control lines and benchmark
• Releasing glass before frame sizes are final
• Leaving a transition detail undrawn and letting the field improvise it
• Surveying slab edges after the embeds are poured instead of before

Takeaway: Nothing gets cut until the shop drawings are approved and the openings are measured against control lines — fabricating from assumptions is how custom aluminum arrives the wrong size.

Educational content only — not design, engineering, or a safety program, and not a substitute for training under a qualified glazier or review by a licensed design professional. Follow the building code and energy code as adopted in your jurisdiction, the project documents, the manufacturer's installation instructions, OSHA 29 CFR 1926, and your employer's procedures.