Application  >  Roof - Above rafter insulation

Roof - Above Rafter insulation

Natural wood fibre sheathing & sarking insulation boards, such as the Steico Universal board, are installed over the roof rafters / trusses to provide an insulating and water protective layer against the elements.


  • Immediate weathering protection – up to 12 weeks
  • Hydrophobic - repels water (acts as a sarking board)
  • Excellent insulating properties reducing thermal bridging in the roof elements
  • Vapour open allowing trapped moisture within the roof component to escape
  • Excellent soundproofing qualities
  • Tongue & Groove on all 4 sides preventing unwanted air drafts
  • Prevents dust blowing into the building envelope
  • Provides structural strength to the roofing element
  • Good fire resistant qualities
  • Easy to cut & install 
  • Save $ on a duplicate membrane...
Installation process is easy
Check out this video of a rigid insulation board being installed over rafters

Installed on pitched roofs.
The natural woodfibre boards can be installed on any pitched roof.  


No additional waterproof measures are necessary for pitches over 18 degrees.


Installed on flat roofs
Boards with a straight edge profile are available with thicknesses of  20mm  to 240mm.

Water repellent boards

The wood fibre insulation boards are hydrophobic meaning they repel water.

Boards can be left unfinished for several months allowing you to get your house secured from the elements


For low pitched roofs with increased requirements for rain protection.

Boards with integrated weatherproof membrane & self-adhesive strip, such as steico Safe, are also available.


Typical Roof detail  

A double batten system is used to fix the boards to the rafters and for the fixing of the roof cladding (Roof tiles or metal sheets). The space between the battens provide an air gap for air flow and for the evaporation of any trapped humidity in the roof envelope.
Roof insulation sample.jpg
Below are some generic details for tiled roofs. However same principal applies for roofs with metal sheets.
Need more technical information ?

You can download the Installation Guides to the Rigid insulating  Sheathing & Sarking boards;  as well as the Product Data Sheet at our Downloads section.