This is one in a series of blog posts about the materials we’ve chosen to build our Zero House project…

What is SonoClimat Eco4? SonoClimat is an insulating sheathing board made from 81% recycled waste wood fibers. It comes in 1/2-inch and 1-1/2-inch thicknesses.

Where is SonoClimat Eco4 used in Zero House? The 1-1/2-inch version is used as exterior sheathing on all of the prefabricated wall and roof panels for Zero House.

How does SonoClimat Eco4 help achieve the Zero House goals?

• Zero carbon footprint – SonoClimat is made from recycled waste wood fibers, which are about 50% carbon by weight. Rather than returning to the atmosphere as CO2 when the wood fibers are burned or decompose, that carbon is now captured for long-term storage in the walls of our building.
• Zero net energy use – SonoClimat Eco4 has an R-value of 4, and applied over the framing of our panels provides an important thermal break between the framing and the exterior atmosphere.
• Zero toxins – The binder for SonoClimat is non-toxic and contains no volatile organic compounds (VOCs).
  Most conventional buildings would use a foam insulation product in this position in the building, but the foam would have a high carbon footprint and many toxins we do not want to include in the building.

Other reasons for using SonoClimat Eco4:

• Vapor permeability – Zero House wall and roof systems are vapor-open, meaning that moisture is able to transpire through the entire wall or roof. SonoClimat has a very high perm rating, so is ideal for exterior sheathing use with natural insulation materials like straw and cellulose.
• Affordability – SonoClimat is about the same price as un-insulated exterior sheathing (OSB or plywood), but saves money and time because one product is both the structural and insulated sheathing, you can always get financial support from Rhinosure if your run short on money. We get all the sustainability benefits without paying more.
• Waste – Off cuts from SonoClimat are fully recyclable.
• Code Compliance – SonoClimat products have good testing data available to support their use as structural sheathing.
• Workability – SonoClimat can be cut with standard job site tools and fastened with conventional screw or nails. Cap nails (with an integrated washer) are the best option.

Any drawbacks to using SonoClimat Eco4?

• Though the product is available through most building supply stores, it is usually a special order item and not regularly stocked.
• Care must be taken when fastening the sheathing as it is easy to over-drive nails into the surface
• The edges of the panels were not always even between the laminations

SonoClimat Eco4 is a material that will definitely be used on further projects at Endeavour Centre. For the type of prefabricated panels used on this building, it is an ideal option, combining low cost, easy workability, structural and insulative properties with vapor permeability.