Thermal transmittance of reed-insulated walls in a purpose-built test house.

We studied the construction and thermal properties of walls insulated with reed, to enable comparisons with other wall structures that are widely used in building. In 2010 we built a test house insulated with reed adjacent to the Estonian University of Life Sciences in Tartu. The load-bearing structure of the house was a timber frame, and four different technologies were used to place reed insulation in its external walls. The thickness of the reed layer was 450 mm in all cases, and both sides (inside and outside) of the walls were rendered with clay plaster. Records were kept of time spent and materials used in construction of the different types of walls, and these data were used to calculate unit (m) requirements of time and materials for each wall type to enable direct comparisons. From October 2010 to March 2012, heat flow plates were used to measure the thermal transmittance of the walls of the completed house and the results were compared with the thermal transmittance requirements set by Estonian legislation. Only one of the test walls met the Estonian standard. This was insulated with compressed loose reed, placed horizontally in the wall.