CSLB C-39 Roofing ContractorFlashing, Ventilation and InsulationEasy

A mason is preparing a masonry chimney to receive counter flashing using a reglet method instead of surface-mounting the flashing on top of the mortar. What is a reglet?

  1. AA metal cleat used to fasten drip edge to the fascia
  2. BA groove cut into the mortar joint or masonry to receive and anchor the counter flashing
  3. CA flexible rubber gasket used to seal pipe penetrations
  4. DA type of step flashing shingle used at sidewalls
Show answer & explanation

Correct answer: B. A groove cut into the mortar joint or masonry to receive and anchor the counter flashing

A reglet is a slot or raked groove cut into masonry (or a mortar joint) into which the top edge of counter flashing is inserted and then sealed, providing a cleaner, more weathertight termination than surface mounting.

Why the other options are wrong

  • A. Cleats are fasteners for drip edge/gutters, unrelated to reglets.
  • C. Gaskets are used for pipe boots, not masonry counter flashing.
  • D. Step flashing is a separate sidewall flashing system, not a masonry groove.

Reglet

A groove or raked-out mortar joint cut into masonry to receive and anchor the top edge of counter flashing.

  • Common at chimneys and parapet walls
  • Flashing edge is inserted then sealed with mortar or sealant
  • Provides a cleaner alternative to surface-mounted counter flashing

Memory trick: Reglet = 'ridge-let' groove that lets flashing sit in tight.

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