COP v3.0:penetrations

View Whole Section for External Moisture Penetrations

This section should be read in conjunction with 6 External Moisture Overview and 8 External Moisture Flashings.

A penetration is any hole cut in a roof or wall cladding to accommodate projections such as pipes, ducts, chimneys, roof lights doors and windows.

This section focusses on roof penetrations only. The type of penetration design is determined by:

  • the size of the hole,
  • shape,
  • the roof pitch,
  • the type of roof,
  • the catchment area,
  • placement on the roof, and
  • aesthetic requirements.

Designers are urged to consider what type of penetration design matches the building application and their customer’s needs, and detail accordingly, rather than allow the installer to make an on-site decision.

Many of the penetration details drawn in the Code of Practice (COP) are included in a step by step How -To  Guide published by the Roofing Association of New Zealand.  A copy of this may be obtained by contacting info@roofingassn.org.nz.