Complex custom architectural metalwork · Lesson 1 of 4

Complex custom architectural metalwork: principles and terminology

What makes a flashing or trim job custom and complex, what finished work must do, the shop drawing, samples, mockup and conference that control it, why three specifications give three answers, and what AFS counts as complex.

You will be able to: Classify a custom metalwork request by what makes it complex, name the project documents and who owns each decision, and say what AFS's published limits allow and what a tested edge system means.

10 min · 9 slides · 8 questions

All lessons in this module

Slide 1 of 9

What custom means here

In this course, custom architectural metalwork means flashing or trim that is not a catalog item: it is drawn, approved and checked for one project.

Five things make it complex: its geometry, how the metal behaves, its finish, the movement it must allow and the other work it meets.

At a glance: the five things that make a piece custom and complex. The 10 to 40 ft range is the lowest and highest maximum spacing in the three public specs used in lesson 2.

Sources

Section 07 6200 Sheet Metal Flashing and Trim (master specification, UH Master 06.2020) - University of Houston Facilities Planning and Construction
UFGS 07 60 00 Flashing and Sheet Metal (August 2023, Change 1 05/25) - Unified Facilities Guide Specifications (USACE, NAVFAC, AFCEC), published on the Whole Building Design Guide

Glossary

Shop drawing: A drawing of how a piece is formed, joined and fixed for one project, submitted for review before fabrication; UH asks that it show plans, elevations, expansion-joint locations and keyed details.
Mockup: A built sample of typical conditions, used to verify sample selections and set the quality standard; UH lets an accepted mockup be built into the project.
Field measurement: A dimension taken on the building, before shop fabrication, so the piece fits what is really there; UH has the contractor notify the Architect/Engineer when it differs from the contract documents.
Complex profile (AFS): In AFS's fabrication limits, a profile with more than one bend or any hem. It is an AFS rule term, not an industry definition.
Movement joint: A joint built to let a run of metal expand and contract; each of the three public specs sets its own maximum spacing between them.
Fixed point: The place where a run of metal is held so it cannot slide. McElroy's bulletin measures movement over the length from the point of fixity to the floating edge.
Oil canning: Visible waviness in the flat areas of metal; technically elastic buckling or stress wrinkling, and it can occur in steel, aluminum, zinc or copper.