Field Data on Settling in Loose-Fill Thermal Insulation

Abstract

Blown loose-fill thermal insulation was introduced to Sweden in the late 1970s and has become more common since then. Today loose-fill insulation is used especially for attics, both as insulation in new building production and as additional insulation in older buildings. Loose-fill insulation is mainly manufactured from mineral wool and cellulosic materials. As users of loose-fill thermal insulation know, this insulation type can settle, which means that it will compress. It is of great importance to know the long-term behavior of the insulation thickness, so as to be able to estimate the insulation capacity during the lifetime of the structure. This paper reviews a field study of settling in loose-fill thermal insulation performed by the National Swedish Institute for Building Research. The study is confined to the use of loose-fill insulation for horizontal structures and formed part of a wider project in which a laboratory study also was performed. In the field study both mineral wool and cellulosic loose-fill materials were investigated. The loose-fill materials were blown on several test attics, and settling was measured during one year within the project. The paper presents results of settling after three years in practice.