Ventilated air space separated from mineral wool by Elastic thin wind barrier sheet will be narrower because of elongation of the sheet and spring of the mineral wool. This means that performance for vapor desorption and drainage of the air space will be insufficient. Measurement and observation on experimental walls with various wind barrier shows that a little elongation of the sheet shut up the air space. Not only elongation of the sheet but also mineral wool type affect to the size of air space.
