bio-based insulation
Bio-based insulation is an innovative solution that utilizes sustainable materials to provide thermal insulation for homes and buildings. By harnessing renewable resources, it not only reduces energy consumption but also minimizes the environmental impact. This eco-friendly option offers excellent performance while contributing to a healthier indoor environment.
Proposals for improving E,F,G, labels in Heemskerk for housing corporation "woon op maat"
Most common bio-based insulation materials are cellulose, cotton, cork, flax, grass (hay), hemp, straw, wood and wool.
Except for wool, all of these materials are plant based. All of these materials are combustible. When plant based materials get exposed to moisture they will rot and mould can grow. To prevent this, the materials should be kept dry or should be able to dry out after getting wet. All of these materials are damp-open. This means that moisture that will occur when outside temperatures are lower than on the inside can travel through the material to be ventillated out by the outside air. The major advantage of this is that when the facade structure is build in the right way moisture is not trapped inside the building. This reduces the risk of mould growth inside and leads to a healthy inner climate. A ventilated cavity facade, where the outer lining keeps rain away from the insulation and the cavity allows condensation to be ventillated away works very well with biobased insulation, espicially where there are no restrictions to the facade because of fire safety.
A ventillated cavity facade, as shown below, works well with biobased insulation. Fire stopping in the cavity be important if the insulation and / or the outer lining are combustible
Flax mat
λ: 0,036 w/mK tot 0,040 w/mK
A good alternative for mineral wool in a project where fire resistance is not an issue. For example mineral wool has a λ of : 0,033 w/mK tot 0,040 w/mK. The main difference is that mineral wool is not combustible.
Flax insulation was used in our project "Boere Jonkerstraat" see our project page for more information on this project >>
Wood fiber mat
λ: 0,036 w/mK tot 0,040 w/mK
A good alternative for mineral wool when no fire resistance is required. For example, mineral wool has a λ of : 0,033 w/mK tot 0,040 w/mK. The main difference is that mineral wool is not combustible.
Wood fiber board
λ: 0,040 w/mK tot 0,047 w/mK
Denser than wood fiber mat and solid enough to form a stable board that can be used as a base for render. The company Claytech which offers sustainable alternatives for plaster board has different product that use woodfiber board as a substrate.
Cellulose
λ: 0,037 W/mK
Cellulose insulation is made from recycled paper and wood chips. Although the thermal insulation properties are very good the hydroscopic (sponge like) properties are very high as well. Cellulose should not be used in walls or roofs close to wet rooms and the the materials itself is conbustible. When the material is packed densly in a wallconstruction combustability is slightly better but usually a toxic agent (boric acid) is added to mitigate fire risk. We do not understand the effect of exposure to boric acid on health of residents and construction workers.
Hemplime
λ: 0,071 w/mK
Hemplime is a mixture of hemp shives and lime. The lime is a binder that, as it hardens, can form a solid volume with the hempshives. Hemplime is stable enouh to be used a (non structural) partitions and infill panels in facades. because of the lime this mixture is less combustible than most bio-based insulation materials
Biobased insulation materials offer an eco-friendly alternative to traditional insulation, but their combustibility is a concern. While these materials are made from renewable resources, it's important to ensure fire safety. Building codes and regulations should be followed to mitigate fire risks associated with biobased insulation. Always consult with professionals to choose the right product for your specific needs.