Pitched Metal Roof with Flat Ceiling

ICANZ System Reference R0200

Structure

Metal roof at 22.5o pitch, 40mm battens, reflective insulation, attic space, 10mm plasterboard flat ceiling.

Foil products are fitted under battens or draped over battens to create an average 40mm airspace facing metal roof.

Insulation installation

Foil faced blanket product shall be installed with foil facing attic space with the blanket compressed over battens. Blanket must be allowed to recover to its full thickness. Reflective insulation shall be draped over battens to create a 40mm air space, antiglare side facing outwards. All joins in foil should be lapped 150mm and tears or gaps in foil sealed with a suitable reflective foil tape.

To maintain the reflective insulation effectiveness, any tears or gaps shall be repaired with a suitable reflective foil tape.

R3.5 batts positioned between joists on ceiling lining.

NOTE: Total R-Values can be increased by substituting bulk insulation products of higher Material R-Value.

A. In accordance with AS/NZS 4859.1:2002.  Amendment 1. 2006.

B. Temperatures and parameters are based on Australian climate assumptions. Air temperature difference 12oC (36oC less 24oC) for summer conditions and 6oC difference (18oC less 12oC) for winter.

C. Thermal resistance of air films and attic spaces based on values obtained from Section K5 and K6 of AS 4859.1:2006.

D. Building material elements based on 2000 AIRAH Handbook and attic thermal value based on AS4859.1 app K6 table K2.

E. Where reflective insulation is installed, a simple addition of R-values is not possible. Care must be taken to ensure the performance of reflective air spaces is not “double-counted”.

F. The emittance of the reflective surfaces are dependent on tested values and the conditions of the installation, as specified by AS/NZS 4859.1. Amendment 1. 2006.