The NZ Metal Roof and Wall Cladding Code of Practice is a comprehensive design & installation guide, and a recognised related document for Acceptable Solution E2/AS1 of the NZ Building Code.
When profile closures are used at the eave, they should be a closed cell and a vented or perforated type to allow some ventilation.
Filler blocks exclude wind, rain, snow, wind driven debris, insects, rodents and birds. Bird damage to the closures caused by pecking or other vermin damage can be minimised by using scribed metal flashings or caps in place of foam fillers or to cover the fillers. Filler blocks can be adhered to metal profiles before or after fixing by using a spray contact adhesive or heat resistant double-sided tape.
Closures are manufactured from closed cell plastic infill strips to match most metal and plastic cladding profiles and are available in most profiles in 'over and under' configurations.
Closures should be used as a wind baffle and should not be used as a prime source of preventing water entering a gap, as the retained moisture will cause corrosion.
They should be used compressed between the sheets and supports or flashing and should be fastened or adhered to the cladding by tape or adhesive to avoid falling out or rolling over. They should be used on all roof pitches below 10° when the wind design load is high or very high.
Closures should be placed midway in the cover gap between the stopend and the front of the flashing which avoids water ingress by providing an air gap baffle to reduce the pressure differential.