Description

A BRANZ project has been investigating alternative options to retrofitting insulation to timber-framed walls with direct-fixed cladding and without underlay.

Some reports suggest that adding insulation to the existing exterior walls with direct-fixed cladding and without underlay may change the path of rainwater leaks, increasing the risk of water transfer from the back of the cladding to insulation and framing as well as reducing the drying potential of the wall. BRANZ investigated this in direct-fixed weatherboard walls, aiming to find potential solutions to improve our homes.

Scope

This article includes:

• Developing retrofit insulation options
• What we did
• Initial results
• Additional testing
• Conclusion
• Repair framing before retrofitting