Division 07 - Sheet Metal Flashing & Trim

  1. This information provides guidelines for flashings and counter-flashings, gravel stops, scuppers, sheet metal gutters, down spouts and rain leaders. Temporary facilities and controls are covered in other parts of these standards or are available from the Facilities Management (FM) project representative.
  2. FM project representative, Public Safety Office, and Environmental Health and Safety Office shall approve selection of materials, means, and methods. Unless otherwise approved, design intent requires means and methods that provide minimal disruption to adjacent building activities and operations.
  3. Comply with SMACNA standards and recommendations.
  4. Sheet metal materials:
    • Galvanized steel: 24 gauge. 
    • Provide factory finish whenever possible.  Use “Flioroceram Kynar 500® PVF” paint finish; select from standard color chart.
  5. Copper:  
    • 20 oz. per sq. ft., unless otherwise indicated.
  6. Aluminum:
    • Minimum 0.050" thick.  Prefer anodized finish.
    • Alloy and temper as required to suit forming operation and finishing operations, conforming to ASTM B209.
  7. Stainless steel:    
    • 24-gauge stainless steel, AISI 302/304, AISI 314/316 in chemically corrosive or sea water environments.  Prefer Smooth #2 finish.
  8. Fasteners: 
    • All items of material matching or compatible with material being installed; non-corrosive; size and gauge as required.
    • Staples prohibited. 
  9. Vent pipe flashing:
    • Lead, at least 1/16" thick or 4 lb. /sq. ft. Provide two-part system with base sleeve sized to slip over pipe, with pre-manufactured cap that overlaps base.  Base flashing soldered to skirt at slope of roof and extending at least 4" from pipe onto roof.
    • Where lead flashing cannot be folded or capped at the top edge, provide 0.060 mil EPDM boot with stainless steel hose clamps.
  10. Warranty: Provide a labor and material warranty for correcting failure of metal flashing system(s) to resist penetration of water for a minimum of 2 years.
  11. Recommended detailing:
    • Flashing materials shall form primary weather protection.  Avoid use of sealants and caulking as primary weather element protection.
    • Isolate dissimilar materials from galvanic corrosion.
    • Lap roof membrane completely under perimeter roof flashings.
    • Where weathertight lapped or formed seams are not possible, create soldered monolithic flashing for complex transitions.
    • Extend flashings under underlayment materials and building papers so that moisture is channeled toward the exterior of the building. 
    • Prefer removable perimeter roof flashings and reglets to facilitate re-roofing.  Avoid embedded perimeter roof flashings. 
    • Allow for thermal expansion and contraction in all detailing.  Concealed slip fasteners preferred wherever possible.
    • Verify gauge thickness will resist deformation and “oil canning” based on the maximum size of exposed flat faces.
  12. Sealants: Preferred applicable sealants are Vulkemor or Butyl by Tremco.

Latest update

2023-11-06