CAD detail standards and coordination · Lesson 4 of 4

CAD detail standards and coordination: defects, verification and case study

Eight common detail defects with corrections, a review checklist, the case where a 36 in wall height was read as a coping leg, and what to send with a packet.

You will be able to: Diagnose a drawing or coordination defect, state the corrective options, and document the evidence for review, including the wall-height case.

10 min · 11 slides · 6 questions

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Slide 1 of 11

Eight defects to look for

Eight defects to look for in flashing details: a butted coping, a cleat fixed tight, an untested substitute, a gauge without a metal, a dimension on the wrong element, an unrecorded unit, a drawing that disagrees with the specification, and a control layer that stops at the parapet.

Sources

Roofing Detail: Coping-to-Wall Termination (February 3, 2011; composition credited to Wendy Zaremba-Just) - Building Enclosure (BNP Media)
ANSI/SPRI ED-1 Design Standard for Edge Systems Used with Low Slope Roofing Systems, PROPOSED revision of October 2025 (not an approved edition) - SPRI
ANSI/SPRI/FM 4435/ES-1 Test Standard for Edge Systems Used with Low Slope Roofing Systems (approved November 21, 2022) - SPRI
FAR 52.236-21 Specifications and Drawings for Construction (FEB 1997) - General Services Administration (acquisition.gov)
Insight 050: Parapets: Where Roofs Meet Walls (Joseph W. Lstiburek, June 2011, rev. 04/2012) - Building Science Corporation
AFS CAD generator and CAD reader: how AFS writes and reads a flashing section in DXF - Architectural Flashing Supply

Glossary

Termination metal: Metal at the top of wall flashing that closes the joint between the wall and the coping. A trade article calls leaving it out and butting the coping to the wall the most common coping mistake.
Attribution: In AFS's CAD reader, tying each dimension and note to the drawn element it measures or describes, so a number is never read as belonging to the wrong part.
Control layers: The water, air, vapor and thermal control layers of a roof and wall. Building Science Corporation says those of the roof connect to the wall's at a parapet.
Synthetic test drawing: A made-up test drawing, built to reproduce a defect. AFS's wall-height case comes from one, not from a customer's drawing.