CATHEDRAL OR SKILLION CEILINGS
Cathedral and skillion ceilings offer a modern, open feel but without the right insulation, they can be prone to heat loss or gain. Foilboard Insulation is the ideal solution for these roof types, providing a rigid, reflective barrier that enhances energy efficiency while fitting neatly within tight ceiling cavities. Enjoy year-round comfort without compromising on style or space.
INSTALLATION ACCESSORIES
Depending on your application, choose one of the following:
-
Timber Fasteners: Use when fixing Foilboard to timber using nails.
-
Steel Fasteners: Use when fixing to steel using screws.
-
Blank Plate Fasteners: Use when supplying your own nail or screw (non-standard fixings).
**Foilboard Insulation Panel Dimension: 240mm x 1200mm (2.88m2)**
Total System R Values Cathedral or Skillion ceiling (22.5° Slope)
FOILBOARD PANEL | HEAT FLOW UP | HEAT FLOW DOWN |
|---|---|---|
GREEN 50 | Rt2.2 | Rt2.7 |
GREEN 25 | Rt1.7 | Rt2.2 |
System Description: 22.5 Degree Pitched Metal Roof, Layer of reflective sarking (E0.03 facing down), Foilboard Between Rafters, 70x 35mm Timber Battens at 600mm spacing, 140x 35mm Rafters at 600mm Spacing, Foilboard under battens antiglare up, Ceiling batten (28mmx38mmx0.55 BMT), 10mm Plasterboard Ceiling. Assumed airspaces are fully sealed and have been designed specifically to prevent air ingress. Calculation based on slight dust cover. Calculation per AS/NZS 4859 Parts 1 & 2:2018.
If elements of construction vary from that described, this may produce a different thermal resistance result.
Higher Total System R Values Cathedral or Skillion ceiling (22.5° Slope)
FOILBOARD PANEL | HEAT FLOW UP | HEAT FLOW DOWN |
|---|---|---|
GREEN 50 (Dual Layer) | Rt3.9 | Rt5.3 |
GREEN 25 (Dual Layer) | Rt3.0 | Rt4.7 |
GREEN 25 (Dual with Blanket) | Rt4.1 | Rt4.9 |
GREEN 50 (Dual with Blanket) | Rt5.0 | Rt5.1 |
System Description Dual: 22.5 Degree Pitched Metal Roof, Reflective Sarking (E0.03 facing down), Foilboard Under Battens/35mm Reflective Airspace above adjusted for sag in sarking/18mm Below, Foilboard Between Rafters Reflective Airspace Below, 70x 35mm Timber Battens at 600mm spacing, 140x 35mm Rafters at 600mm Spacing, Foilboard between rafter's antiglare up, ceiling batten (28mmx38mmx0.55 BMT) bottom of rafter, 10mm Plasterboard Ceiling. Assumed airspaces are fully sealed and have been designed specifically to prevent air ingress. Calculation based on slight dust cover. Calculation per AS/NZS 4859 Parts 1 & 2:2018
​
​
System Description Dual with Blanket: 22.5 Degree Pitched Metal Roof, 60mm Insulation Blanket R1.3 (E0.03 facing down), Foilboard Between Rafters, 70x 45mm Timber Battens at 600mm spacing, 140x 35mm Rafters at 600mm Spacing, Foilboard between rafter's antiglare up, ceiling batten (28mmx38mmx0.55 BMT), 10mm Plasterboard Ceiling. Assumed airspaces are fully sealed and have been designed specifically to prevent air ingress. Calculation based on slight dust cover. Calculation per AS/NZS 4859 Parts 1 & 2:2018.
If elements of construction vary from that described, this may produce a different thermal resistance result.
If the R-Value required for your project is not listed in the table above, please complete the Roof R-Value Request Form and submit the necessary project details.
DISCLAIMER All statements and technical information contained herein are based on tests we believe to be reliable, but the accuracy thereof is not guaranteed. Users assume all risk and liability resulting from the use of the product and must confirm the suitability thereof by their own calculations. Conditions of Sale contain a limited warranty against manufacturing defects. Where applicable, Foilboard GREEN should be installed per the National Construction Code (NCC), state building legislation and/or a performance solution.
Added Insulation R Values Cathedral or Skillion Ceiling (22.5°)
FOILBOARD PANEL | ADDED INSULATION R VALUE HEAT FLOW UP | ADDED INSULATION HEAT FLOW DOWN |
|---|---|---|
GREEN 50 | R2.1 | R2.7 |
GREEN 25 | R1.5 | R2.2 |
System Description: 22.5 degree pitched metal roof, layer of reflective sarking (E0.03 facing down), Foilboard panel between rafters, 70mm x 35mm timber battens at 600mm spacing, 140mm x 35mm rafters at 600mm spacing. Foilboard under battens anti-glare side up. Ceiling batten 28mm x 38mm x 0.55 BMT, 10mm plasterboard ceiling. Assumed airspaces are fully sealed and have been designed specifically to prevent air ingress. Calculation based on slight dust cover. Calculated per AS/NZS 4859, Part 1&2 2:2018. Added insulation R value includes the material insulation R value and the R values of the associated reflective airspaces within the insulation system pathway. If elements of construction vary from that described, this may produce a difference thermal resistance result.
Higher Added Insulation R Values Cathedral or Skillion Ceiling (22.5°)
FOILBOARD PANEL | ADDED INSULATION HEAT FLOW UP | ADDED INSULATION HEAT FLOW DOWN |
|---|---|---|
GREEN 50 (Dual) | R3.8 | R5.0 |
GREEN 25 (Dual) | R2.8 | R4.3 |
GREEN 25 (Dual with Blanket) | R4.0 | R5.1 |
GREEN 50 (Dual with Blanket) | R5.0 | R5.7 |
System Description Dual: 22.5 Degree Pitched Metal Roof, Reflective Sarking (E0.03 facing down), Foilboard Under Battens/35mm Reflective Airspace above adjusted for sag in sarking/18mm Below, Foilboard Between Rafters Reflective Airspace Below, 70x 35mm Timber Battens at 600mm spacing, 140x 35mm Rafters at 600mm Spacing, Foilboard between rafter's antiglare up, ceiling batten (28mmx38mmx0.55 BMT) bottom of rafter, 10mm Plasterboard Ceiling. Assumed airspaces are fully sealed and have been designed specifically to prevent air ingress. Calculation based on slight dust cover.
​
System Description Dual: 22.5 Degree Pitched Metal Roof, 60mm Insulation Blanket R1.3 (E0.03 facing down), Foilboard Between Rafters, 70x 45mm Timber Battens at 600mm spacing, 140x 35mm Rafters at 600mm Spacing, Foilboard between rafter's antiglare up, ceiling batten (28mmx38mmx0.55 BMT), 10mm Plasterboard Ceiling. Assumed airspaces are fully sealed and have been designed specifically to prevent air ingress. Calculation based on slight dust cover.
Calculation per AS/NZS 4859 Parts 1 & 2:2018. Added Insulation R Value includes the material insulation R Value and the R Values of the associated reflective airspaces within the insulation system pathway.
If elements of construction vary from that described, this may produce a different thermal resistance result
If the R-Value required for your project is not listed in the table above, please complete the Roof R-Value Request Form and submitting the necessary project details.
DISCLAIMER All statements and technical information contained herein are based on tests we believe to be reliable, but the accuracy thereof is not guaranteed. Users assume all risk and liability resulting from the use of the product and must confirm the suitability thereof by their own calculations. Conditions of Sale contain a limited warranty against manufacturing defects. Where applicable, Foilboard GREEN should be installed per the National Construction Code (NCC), state building legislation and/or a performance solution.