Roof ventilation #3: Air permeability of common New Zealand ceilings and ceiling penetrations (November 2018)

BRANZ has tested the air permeability of a range of common ceiling types and fixtures. Acoustic tiles were by far the leakiest type of ceiling, and old-style incandescent downlights allowed by far the largest amount of air leakage into the roof space. The findings can help address the problem of moisture being transported into airtight roof spaces.

Read the full report here.