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Retrofit Wall Insulation Options

Written by Blow Insulation on .

Retrofit Wall Insulation Options

We all know that the majority of New Zealand’s ageing housing stock is not adequately insulated, and while an effort is being made to retrofit ceilings and floors, the absence of retrofit wall insulation options dramatically reduces the benefit of this effort. 

The key to good thermal performance is a completed thermal envelope – and without adequate wall insulation this is not attainable.

A variety of retrofit wall insulation options have been used to insulate New Zealand homes. Traditionally these were installed by small-scale operators with limited technical capabilities using products such as blown cellulose or sheep’s wool. The absence of regulated installation systems and quality moisture repellent materials put off most consumers which resulted in very few homes being retrofitted using these technics.

Expanding wet foam systems, installed via small holes in the linings, gained popularity during the 2000’s, but clarification on the requirement for building consents; coupled with bad publicity (mainly focused on the shrinkage of the foam), reduced the popularity of this system. 

The good news is there are new alternatives to removing the linings or cladding with retrofit wall insulation. Blown insulation systems are again making retrofitted wall insulation viable, and there are a number of solutions available. 

If you are considering retrofitting wall insulation it is important to choose a company that uses an audited system. This should include assessment of the building to ensure it is suitable and the product shouldn’t introduce moisture to the cavity during installation. It should feature some form of water repellency, a proven cladding reinstatement method and documentation showing compliance with the NZBC.  

The installation of all wall insulation requires a building consent, but exemption may apply to systems in some areas. A reputable company can help you through this process and ensure you get a great result from the new retrofitted wall insulation.

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