Insulation in older properties usually boils down to 3 determining factors,…money, conservation stipulations and change of building profile. Identification of materials used and how they have been constructed is crucial, also accessing breathability, as a single wall will often contain more than one material with quite different performance characteristics.
Sheep’s wool, in various sizes and thicknesses we have found to be one of the best forms of natural insulation and possesses virtually zero moisture holding levels. Easily cut to size and installed between open stud work , making it a favoured option within timber framed buildings, both for external and internal plaster work.
Cork sheets come in various thicknesses and are best suited to Brick / Stone built properties. Cork, with its inability to absorb moisture, is an ideal candidate for external and internal cladding. Fixed with mechanical fixings and finished with a 25mm coat of lime plaster, it’s only downside is that externally it alters the profile of the walls with regard to windows and doors and internally slightly shrinking room sizes.
Another additional form of insulation is Savolit Plus. These are wood wool boards that consist of long, strong wood fibres that are mineralised and bonded on to panels of various sizes. Handy for a base board to plaster ceilings and timber frame walls, it does away with the need to use laths. Coupled with sheeps wool insulation, it gives a strong permeable structure, enabling good breathability and vapour release.
Correctly specified materials and understanding a buildings requirements are key. Many firms posing as Conservation / Restoration specialists, having limited knowledge on the subject, continue to operate using modern materials, all of which accelerating existing problems and or creating new ones.