Mule-Hide Blog

Back to Blog

Penetrations Through Vertical Flashings

Posted: 2/1/2019

Why?  Why?  Why?


These photos were taken during one of our warranty inspections.

The following images may be offensive to some roofing contractors


How does this even happen?  Regardless of the trade involved on a project, haphazardly punching holes through your waterproofing membrane is not an acceptable situation.

Believe or not, this kind of thing happens all of the time.  Granted, this is an extreme case but understanding some design considerations and Mule-Hide’s requirements for flashing penetrations through vertical flashing is important for all trades on a construction site.  More importantly, communicating this information to all those trades is critical to preventing it from happening.

Design Considerations

  • Avoid all penetrations through vertical flashings.When absolutely required, reduce the number of penetration points to as few as possible.
  • Try to ensure that the penetration point is 8” or higher off of the roof surface and projects far enough away from the wall to allow adequate clearance to install the appropriate flashings.
  • Avoid flexible conduit or cabling whenever possible because that flexibility will eventually break any seal made at the termination.
  • Keep all penetrations to 1/2” diameters or larger to make field fabricated flashings easier to install.
  • If flexible conduit, cabling or penetrations less than ½” in diameter are unavoidable, install rigid gooseneck type sleeves.Flash the rigid sleeve and pass the flexible components through the gooseneck.
  • Stub out any conduit needed for electrical before the roofer flashes the wall.This will allow the roofing contractor to slip a pre-molded pipe boot over conduit during construction.The rest of the required conduit can be added to the stubbed-in piece and the wire pulled after the roofer is done.

Mule-Hide Flashing Requirements

  • Mule-Hide ShapeShift Pitch Pans:ShapeShift Pitch Pans provide a roofing contractor with a unique solution to vertical flashing penetrations.ShapeShift pans can be installed on vertical surfaces when filled with JTS 1 sealant.ShapeShift pitch pans are recommended on Mod. Bit. / BUR roofs and on projections ½” in diameter or smaller.Watch our ShapeShift video for more information
  • Pre-Fabricated Pipe Boots:Pre-Fabricated Pipe Boots can only be installed if they can be slipped over the top of the projection.Pipe Boots cannot be cut and re-sealed to go around a projection.Running multiple penetrations through a pipe boot or leaving pipe insulation under the banding clamp are not approved.Mule-Hide Pre-Fabricated Pipe Boots are designed for the following diameters:
    • EPDM – 1” to 6”
    • TPO – ¾” to 8”
    • PVC – ¾” – 8”
  • Split Pipe Seals:If a pipe boot cannot be installed, Mule-Hide provides TPO or PVC Split Pipe Seals in 1 to 6 inch diameters.Running multiple penetrations through a split pipe seal or leaving pipe insulation under the banding clamp are not approved.Mule-Hide does not make split pipe seals for EPDM projects.
  • Field fabricated flashing:Field fabricated flashing are generally easier in EPDM systems than TPO, PVC or mod bit systems.Projections smaller than ½” in diameter are very hard to field flash.
Back to Blog

Theme picker