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Improvement of traditional clamped joints in vapour- and wind barrier layer for passive house design


The harsh Norwegian climate requires buildings designed to high standards. An airtight
building envelope is critical to achieve an energy efficient building and to avoid moisture
Use of clamped joints is a traditional way to make airtight joints in the wind- and vapour
barrier in Norway and other countries. In houses designed according to passive house
standards the air tightness of the building envelope is critical. It may be questioned weather
this traditional method is sufficient, and how it may be improved without applying extra
sealants such as adhesive tape.
The air tightness of clamped joints depends on several parameters and some of them have
been investigated in a laboratory study. The resistance to penetration of air through pinched
joints in the wind- and vapour barrier was tested in accordance with EN 12114.
The test samples were made by clamping two sheets of PE-foil with specific size between a
batten and a stud. The samples were mounted in a test rig in order to measure the air leakage.
The measurements were conducted with different thicknesses of the batten, different sizes of
nails or screws and various center distances of the nails or screws. Measurements were
conducted at delivery moisture content of approximately 0,17 kg/kg, and after drying to
approximately 0,07 kg/kg.
Before drying out most of the test samples were very air tight. The air leakage increased
considerable after drying. This shows the importance of maintaining a dry building process,
something which for example can be achieved by use of prefabricated wooden elements.
Results from the measurements were used to calculate and estimate leakage numbers for two
case buildings.
The research has been performed within the smartTES project (


Academic chapter/article/Conference paper





  • SINTEF Community / Architecture, Materials and Structures
  • Norwegian University of Science and Technology




Akademika forlag


PassivhusNorden 2012



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