Vapor permeable insulation solutions for roofs and external walls

We supply a range of Steico weather-proof vapor permeable wood-fibre, insulation products (boards & batts ) or all types roof and external wall construction: (Timber, CLT, Masonry, Steel.)

Sarking & sheathing boards

For above roof rafter / external wall

Insulation batts

For between roof rafter / stud walls 


Our products are Passive House Certified components

Benefits to insulating above
the rafters & external wall


Installing wood-fibre insulation boards above the roof rafters & on the external walls has numerous benefits, which include:

  • Reducing thermal / cold bridging in the building elements
  • Creating a warm roof / external wall
  • Diffusion-open insulation materials for safe moisture management
  • Providing an additional water & wind protection layer 
  • Reducing external noise pollution
  • Provides weather protection for up to 8 weeks during construction; helping to keep your building dry

Sarking & sheathing wood-fibre insulation board for above roof rafters / external walls

We carry the Universal, Protect H and Special Dry wood-fibre boards from Steico. These boards are classified as sheathing and sarking boards, meaning they can support a load, and are also rain proof.  i.e., water-repellent. Rainwater’s surface tension cannot break through sarking boards.

The wood-fibre permeable board come in different densities,  thermal conductive levels, and thicknesses. (Range from 22mm - 240mm)

Boards are available in the "wet" or "dry" mfg process. (Learn more)



Steico Protect-H Board

steico PROTECT-H




Sarking & sheathing render carrying boards

If you wish to render your external wall, the Steico Protect-H board is a combined sarking and render board. It is a waterproof board that can be finished with a natural lime or silicate vapour permeable render.


The boards secured to the building frame using large head specialised screws with a plastic washer. 

Installation process is easy

Fixing the boards

A double batten system is used to fix the boards to the rafters / external walls frame and for the fixing of the roof and wall cladding.  The space between the battens provides an air gap for air flow and for the evaporation of any trapped humidity in the roof envelope.
Need more information on how to install the boards ?

Click on the image to the right to download the Installation Guides: Rigid insulating  Sheathing & Sarking boards.


You can find the Product datasheets in our Downloads  page.


Wood-fiber insulation batts for between roof rafters / external stud walls

We carry the Steico Flex036 vapor permeable wood-fibre batts. These are high density batts that are "friction fitted" between roof rafters and stud walls. They range from 40mm - 240mm thick. 

Roof insulation sample.jpg

• FLEX036 -  thermal insulation batts
• Easy handling and classified as non-irritant to skin
• Good compression resistance strength
• Excellent insulation properties in winter and summer
• Water vapour open & breathable  for a healthy room environment 
• Ecological and environment-friendly, fully recyclable
• Provides a green architectural solution

• Passive House Institute Certified Component