Don't be Foiled! Replace old foil insulation!

As of April 4th 2025, Branz reports that 18% of homes still have foil underfloor insulation! That's a staggering number after almost a decade since foil insulation was outlawed in 2016.

Foil insulation, even before its discontinued use, had become well known as ineffective. It's R value ratings did not match real world performance, and slight variables in application had major impacts on how well it worked as an insulator.

So why is foil underfloor insulation so rubbish?!

WIND - Even a slight breeze!

Even a slight breeze can make your foil underfloor insulation ineffective! Working on the principle of a radiant barrier, an air pocket between the foil and the flooring has to be maintained, and the air in there can't move! As soon as it does, you might as well have nothing there.

Even a slight breeze can make the foil completely ineffective!

Ian Cox-Smith (2016)

DUST - Unavoidable?!

Dust on the foil insulation quickly reduces how well it works as a radiant barrier, and when wasn't the crawl space under your house dusty? If your old floor boards are dropping dust, rodents are building their nests, and dirt is everywhere in your crawl space the foil won't be working properly! And I'm yet to see a foil install without some rodent nests between it and the floor!

DAMAGE - Even a little bit.

Damaged foil is useless and provides little to no help insulating your home. Even a little damage quickly ruins an entire area of the foil insulation. As soon as some of the foil is starting to wear out, replace the lot!

Signs of wear on a couple sheets just shows you what you can't see on all the rest. leaks, rodents, dust, wind and weather have all degraded the foil sheets and you're living in a home that is practically uninsulated under the floor!

In Conclusion...

Foil is a problem, a menace! Getting rid of it earlier rather than later will help you start saving money warming your home and eliminate the growing ugly mess under your house!

Get in touch with our team today for a free inspection and quote!