Question:
Our carpenter wants to use foam sealant to install our windows and doors. We would like to avoid having chemicals in our home. Are there any alternatives?
Answer:
Yes, there are alternatives that we believe are technically superior because they are more durable.
Foams sealants, also referred to as expanding foams, may contain isocyanates, flame retardants, and other chemicals. These substances can have harmful environmental and health effects during manufacturing, application,1 use, and disposal. Health risks can arise from emissions during application and from particles released through aging processes that are inhaled over time.
Image: Installation of hemp cavity insulation (caulking cord and Uckermark hemp fiber) in the IBN building. After installing the cavity insulation, an airtight seal is created between the window frame and the masonry by applying an adhesive tape to the window frame.
We recommend the following alternative:
- Secure windows or doors mechanically using standard metal fasteners. In the past, wooden wedges and shims were used for this purpose, sometimes in combination with dowels and screws.
- Use thermal insulation materials, such as hemp or sheep’s wool, as cavity insulation.2
- Seal joints where exterior walls meet windows and doors with adhesive or sealing tape. These joints must be airtight on the inside and sealed against wind and driving rain on the outside.
1 Therefore, anyone who works commercially with polyurethane (PU) foam sealants in Germany must complete training in accordance with the REACH regulation.
2 Sheep’s wool is ideal for connection joints in exterior walls, but it must be protected from moths. Currently, Isolena GmbH in Austria is the only company with a patented process that does not require insecticides.
This question was answered by Josef Frey from the IBN Team.