The advantages offered by full fill insulation over part fill in masonry cavity walls have been brought into focus by Knauf Insulation. One of their key findings being that the installed cost of DriTherm glass mineral wool cavity slabs show almost a 50% saving over part fill rigid foam boards.Costings were calculated using the SPONS Architects and Builders Price Book 2008 and are based on the requirements for a typical semi-detached house with a target U-value of 0.29W/m2k.
The installed cost is far from being the only benefit - it's also easier to achieve more reliable thermal performance than the alternative part fill rigid foam board solution. The flexibility of DriTherm Cavity Slabs in being able to follow wall contours results in far fewer airspaces on the warm side of the insulation than would be experienced when installing rigid foam boards. With DriTherm, the slabs also knit together at joints preventing heat loss through the gaps commonly associated with rigid foam boards
