Complex custom architectural metalwork · Lesson 2 of 4

Complex custom architectural metalwork: materials, standards and design constraints

How the specs name copper and aluminum, what zinc and aluminum do to forming and joining, movement as arithmetic, why joint spacing differs by owner, oil canning, finishes, metal compatibility and AFS's thickness rules.

You will be able to: Choose a metal, thickness, finish and joint approach that satisfies the governing document, the metal's behavior and AFS's published limits, and explain why three documents can disagree.

12 min · 12 slides · 9 questions

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Slide 1 of 12

Copper and stainless steel in the specs

Copper: UH asks for cold-rolled copper sheet to ASTM B370 in H00 or H01 temper; VA asks for ASTM B370 in cold-rolled temper.

ASTM B370-22 is titled Standard Specification for Copper Sheet and Strip for Building Construction.

VA joins copper over 20 oz and stainless steel over 0.018 in thick by lapping, riveting and soldering.

Sources

Section 07 6200 Sheet Metal Flashing and Trim (master specification, UH Master 06.2020) - University of Houston Facilities Planning and Construction
Section 07 60 00 Flashing and Sheet Metal (national CAD standard specification, header date 10-01-23) - U.S. Department of Veterans Affairs, published on the Whole Building Design Guide
ASTM B370-22 Standard Specification for Copper Sheet and Strip for Building Construction (store scope page; the standard text was not used) - ASTM International

Glossary

Cold-rolled temper (copper): The temper both UH and VA name for ASTM B370 copper sheet; UH accepts H00 or H01.
Expansion coefficient: How much a length of metal grows per degree of temperature rise. In AFS's register it is stated per degree Fahrenheit and used as coefficient x length x temperature change.
Authority having jurisdiction: The body whose requirements apply to a project; McElroy tells designers to consult it for the temperature change to design movement for, because no national standard sets one.
Anodic coating class: AAC sorts anodic coatings by thickness: protective and decorative under 0.4 mil, Class II 0.4 to 0.7 mil, Class I 0.7 mil and thicker; 1 mil is 0.001 in.
Galvanic action: Corrosion where dissimilar metals touch; UH protects against it with a bituminous coating or another permanent separation.
Girth: The total flat width of a profile, hems included. AFS's limit is 48 in, the width of the sheet it forms from.