Is there a difference between glasswool and fibreglass insulation?

Fibreglass vs Glasswool – What is the Difference

Glasswool insulation is made from recycled glass bottles, sand and other materials. Glasswool is just another name for fibreglass insulation. It’s also sometimes referred to as glass fibre insulation or fibreglass segments. These are melted at very high temperatures and then spun into fibres. The result is millions of tiny air-pockets being created inside the insulation, which is what gives glasswool insulation its excellent insulating properties. Knauf Earthwool, Fletcher Pink Batts and Bradford Insulation are among the most popular glasswool brands available in Australia.

Fibreglass Batts – Like Sheep’s Wool and Down Feathers

You may be surprised to learn that glasswool insulation works in a very similar way to natural sheep’s wool and down feathers. Various binders can be used to hold the insulation together. Glasswool segments have for decades been associated with irritation of eyes, nose, skin and throat, but thankfully technological developments have resulted in a vast improvement in the product design, resulting in far softer and more pleasant insulation products now being available on the market. Brands such as Knauf Earthwool have taken the low-itch factor to a new level, and you’d have a hard time guessing that it was indeed glasswool insulation.

Glasswool Insulation – Keep Dry at All Times!

Wet insulation is a dilemma at the best of times, and glasswool insulation is no exception to this. It’s not difficult to understand why wet insulation doesn’t work, and will cause no end of trouble for the home owner if it is installed while wet. Firstly, glasswool relies on the microscopic airgaps inside – technically speaking it’s the airgaps which are the actual insulators. Now if these get soaked with water, there goes your thermal insulation! Also, wet glasswool insulation will be susceptible to mould, and will introduce moisture to whatever area of the building it is installed, with potentially destructive results. For this reason, glass insulation should always be stored high and dry, and if any part of a glasswool segment should become wet, it should be cut off, discarded and never used.

Why is Glasswool Insulation Still so Popular?

Glasswool insulation remains hugely popular, and with good reason. The bulk of the insulation originates from sand, which is one of the world’s most abundant natural resources. Other additional benefits of fibreglass insulation segments is that they are resistant to vermin, and are non-combustible (won’t catch fire) – an obvious bonus considering they are most always installed within the actual building frame. When properly installed in the roof, ceiling or underfloor of a home, glasswool insulation can be expected last as long as the home itself.


Is Fibreglass Insulation Itchy?

All fibreglass insulation can be a little bit itchy to work with, especially if you have sensitive skin. The itch caused by working with modern day quality glass wool insulation isn’t caused by chemicals, but simply by the tiny glass-fibre ends which make up the consistency of the glass insulation. For this reason, it’s recommended to wear a long sleeve shirt and gloves when handling glasswool, and should you still find that your hands and arms are itchy at the end of the day, a good rinse under cold water should resolve that without much trouble.

How is Fibreglass Made?

As the name suggestions, recycled glass is a key ingredient in the manufacturing of glass wool insulation. Together with other ingredients, such as soda ash, limestone and a significant portion of sand, this mix is then heated to melting point, before it is spun into long, super-thin threads of glass fibre. A binder is added to the mix, and after being baked in a large oven, the insulation is sliced up and cooled off, before being packaged.

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