Problems with Cavity Insulation

Adding insulation to wall cavities already partially insulated, is crucial and allows energy savings, comfort and is environmentally positive. But it may be difficult and result in cavity voids... Be aware. Check it with your contractor. Even insulation of empty wall cavities can be tricky.

See also: Cavity Insulation basics

Cavity insulation voids

Cavity Insulation Voids and GapsThe major problem with cavity insulation is voids, associated with settling and insufficient density, namely when the insulation material is blown through holes in the exterior or interior wall surfaces.

If the fill tubes connected to the blowing machine aren’t inserted deep enough into the wall, the necessary density and uniformity may not be achieved, with the resulting gaps and reduction of energy-efficiency.

Requirements

Cavity wall insulation is a well tested technique, without drawbacks in itself. Properly applied, cavity wall insulation will also help to reduce possible condensation problems. But… it’s also a relatively expensive job and a professional task. Filling cavity walls isn’t a typical do-it-yourself job, all the more that it requires special equipment for blowing loose-fill insulation into the cavities.

Qualified installers

To look for qualified installers for cavity wall insulation, consider…

USA and Canada:
Home Energy Rater (to find contractors in your area), or a member of the Insulation Contractors Association of America

UK:
The National Insulation Association (NIA), The Cavity Insulation Guarantee Agency (CIGA), The British Board of Agreement (BBA)

Australia:
The Thermal Insulation Contractors Association

Image above:Dow Chemical

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