Architectural Flashing Supply
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Flashing geometry and movement accommodation · Lesson 3 of 4

Flashing geometry and movement accommodation: methods and worked application

A design sequence from temperature range to fabrication check, worked on a 40 ft aluminum run and on piece joints, with the AFS limits a movement detail must fit and the notes the installer needs.

You will be able to: Apply a documented design sequence to a run of flashing: state the range and fixed point, work the movement, share it across joints, check differing metals, and test the detail against AFS fabrication limits.

12 min · 12 slides · 8 questions

All lessons in this module
Slide 1 of 12

The design sequence

Course guidance from this module's sources, not a published list.

  • Write the design range and source.
  • Mark one fixed point per piece.
  • Work movement each side of install.
  • Choose the joint family and layout.
  • Check joint room at install.
  • Check differing metals.
  • Check AFS fabrication limits.
  • Note what the installer must not do.
  • Run the AFS tools as a check.
The designer's movement sequenceNine boxes from top to bottom: write the design range and its source, mark one fixed point per continuous piece, work the movement each side of the installation temperature, choose the joint family and layout, check joint room on installation day, check differing metals, check AFS fabrication limits, write the installer do-nots, and run the AFS tools as a check.Write the range and sourceMark one fixed point per pieceMovement each side of installChoose joint family, layoutCheck joint room at installCheck differing metalsCheck AFS fabrication limitsWrite the installer's do-notsRun AFS tools as a check

Nine boxes from top to bottom: write the design range and its source, mark one fixed point per continuous piece, work the movement each side of the installation temperature, choose the joint family and layout, check joint room on installation day, check differing metals, check AFS fabrication limits, write the installer do-nots, and run the AFS tools as a check.

The sequence used in this module, assembled from the cited sources. A project specification or maker that sets a different order governs.

Sources

Videos for this lesson

What this video shows: The channel's description says it explores how standing seam roof panels, panel components and flashing details are designed to accommodate thermal movement, with best practices for specific applications. One manufacturer's approach.

Video: Designing and Installing Metal Roofs to Allow for Thermal Movement – AIA CES Nano Course by AEP Span Architectural Metal Roofing & Siding, on YouTube. Chosen from the video's published description.

Glossary

Piece joint
The joint where two lengths of a run meet; in a run of 10 ft pieces every piece boundary is a joint that must take movement.
Installation temperature
The metal temperature on the day a joint is formed; expansion is worked up from it and contraction down from it.
Differential movement
The difference in movement between two connected materials with different coefficients; ED-1 calls for slotted or oversized clearance holes where it occurs.
Girth
The total flat width of a profile with its hems included; AFS's limit is 48 in.
Teardrop hem
A rounded loop at the end of a leg; the third AFS hem type besides open and smashed.
Hem return
The length a hem folds back on itself; AFS needs at least 3/8 in, and its default is 1/2 in.
Engineer of record
The engineer responsible for the design; AFS's thermal method says joint spacing and clip design take validated design rules and the engineer of record.