- How do you source the material?
- Were any glues or binders used?
- How is it treated for fire and insect resistance?
- Is your product guaranteed by any third-party certification?
Sheep’s wool is a great insulator. It’s very efficient and naturally able to handle condensation. It doesn’t clump or settle over time, and it actually can have an air filtering effect, because it has the ability to absorb some airborne chemicals, such as formaldehyde.
There are no synthetic glues used to bind the cork granules into boards. Instead, the granules are heated and the suberin, a natural substance of the material itself, binds it together. Cork can be divided into boards of varying thicknesses.
While cork has been used for quite a while in Europe as a rigid insulation material, the American market will need some time to learn how to work with this relatively new material. As with many rigid insulation materials, it can be difficult to avoid gaps at the joint of the boards, so you will want to overlap the material and pay special attention to tricky spots, like around windows.
One of the major risks with this material is its high flammability, and if not installed correctly, it can pose a danger. That means you would need to be all the more vigilant about finding an installer who is willing to try it out and perhaps be open to the idea of having it inspected for peace of mind.
Hemp fiber has similar properties but is a more rapidly renewable resource and has a lower density.
Depending on the manufacturer, this material can be composed of recycled newspaper or sawmill scraps, but there are also manufacturers who use virgin wood, which is unfortunate, because they are downgrading a valuable material to a job that could easily be fulfilled by wood that has already served other purposes. Even the recycled-newspaper cellulose gives some people pause because of the ink content.
We often recommend that the installer’s work be quality checked during the process by a third party with an infrared camera. This ensures quality of installation for an relatively low hourly cost, possibly avoiding the future cost of fixing or redoing the job.
This article can be found on Houzz.com.