Timber frame wall insulation frame walls is often very poor and they struggle to meet modern expectations in terms of thermal performance. However, retrofit insulation can make a significant difference to the hygrothermal performance of a building and also improve its economic viability. It is important to understand that insulating a wall is not just about improving its U-value, but it is also about reducing the amount of moisture that penetrates and dries out the timbers, as this can cause significant damage and significantly reduce performance.

It is usually best to fit insulation externally where possible, as this is not only more effective in terms of hygrothermal performance but it will avoid damaging existing finishes and the timber itself. It should be noted that the condition of a wall is directly linked to its hygrothermal performance, so unless necessary repairs have been made to remedy dampness and rot, it is unlikely that adding insulation will significantly improve its hygrothermal performance, but will simply mask other issues.

Enhancing Comfort: Timber Frame Wall Insulation Techniques

Fortunately, timber frame construction has the advantage that the load-bearing structure of studs spaced a few dozen centimetres apart can easily accommodate a generous layer of insulation without encroaching on living space. Most of the leading manufacturers supply rigid XPS foam insulation pre-cut to fit snugly between standard stud widths, with varying products and thicknesses available to achieve impressive U-values. These are supplied in sheets which can be cut on-site to the required dimensions, and are easy to fit and install. The addition of a vapour barrier such as TLX Silver, which is installed over the top face of the insulation boards, ensures that the cladding and timber frames remain dry and helps to maintain excellent hygrothermal performance.