London -- An "all-in-one" expanding polyurethane foam tape could play a key role in making energy efficient buildings from straw-filled panels.
A major research project at the University of Bath in the UK is looking into the feasibility of constructing buildings from straw-filled panels, with the gaps between them sealed using a tape made by ISO Chemie GmbH, Aalen, Germany-based producer of impregnated foam sealants and foamproducts.
"ISO Bloco One is being used to provide a high-performance airtight, acoustic and thermal seal between the straw-filled, cassette-style building blocks used to construct the two-storey BaleHaus at Bath on the University's campus" ISO Chemie said, in a 27 May statement.
According to this, the BaleHaus uses the ModCell system, prefabricated panels filled with straw and hemp which provide good thermal insulation. These can allow "super-insulated, high-performance, low-energy or 'passive' buildings to be constructed using renewable, locally sourced, carbon-sequestering materials," the statement claimed.
This means zero heat requirements and savings on costs and carbon dioxide emissions, the company added.
"Strips of ISO Bloco One have been installed in the 10-mm expansion joints between the 3-m2 bale blocks," ISO Chemie explained. This yields a structure offering an air-tight seal: 0.86-m3/hour/m2 measured at 50 pascals, well underthe construction industry norm, which is anything between 3 -- 5 m3/hour/m2," the statement added.
The external seal area, the statement said, provides weather resistance and breathability, while the intermediate seal area provides extra thermal and acoustic properties with the internal seal giving air tightness and humidity regulation. All three levels are designed to accommodate movement between the adjacent materials.
The self-adhesive tape provides a seal for window and door joints up to 30mm wide and is impermeable to driving rain at a minimum of 1000 Pa - "66 percent higher reliability than most conventional joint sealing tapes," the company claimed.
ISO Chemie claims installing Iso Bloco tape helps to better protect a building from elemental factors such as wind, dust and moisture ingress by accommodating the changes in structural movement caused by environmental, cyclical and settlement factors.
The product is compliant with energy saving regulations (EnEV) on windows and doors, meets RAL Quality Assurance Association requirements and is able to accommodate temperature changes from -30oC to +80oC, the statement added. (RD)"