As a result of improved insulation for timber framed houses of the need for buildings to be able to breathe, there has been a move towards more permeable modern insulation materials. However, the introduction of such materials to existing timber framed houses raises many technical and conservation issues.
In some instances insulating the walls of a historic timber frame building may be the only possible means of improving its thermal performance. In such cases it is important that any solution will not compromise the integrity of the original fabric or the character of the building.
“Insulation Solutions for Timber Framed Houses: What to Consider
For some time the common approach has been to introduce internal insulation within the wall cavity. Typically this has involved foil faced or mineral wool boards inserted between timber studs. It has also been usual to add a vapour barrier to this insulation system. Using these techniques it has been possible to achieve impressive U-values for a typical timber frame house.
It is now more common to enclose the timber frame in manufactured panels such as SIPs (structural insulated panels). These comprise an insulating foam core sandwiched between two structural facings – typically oriented strand board – and are capable of covering large areas within timber frames and reducing dependency on bracing and auxiliary members.
However, there is a risk that this type of work will compromise the airtightness of the structure and lead to moisture problems. For this reason, the use of SIPs should be carefully considered and a thorough survey of the timber frame is recommended before such an approach is taken.