Why fibreglass is such a poor insulator

Admittedly after the baking hot temperatures that briefly visited the UK recently, insulation may not be at the front of your queue in thoughts. You know though that even in summer, retailers are planning ahead for winter and Christmas and it won’t be long before seasonal items appear in shops and shorts and T shirts are reduced in price.

Eco Smarthomes are not in that business, but we do think that insulation and cost savings are an all year round priority for your expenditure and the planet.

Rather than generating broad brush strokes of what we can and can’t do from our company base in Chelmsford, we thought we’d zoom in on fibreglass and explain why it is such a poor insulator.

Firstly though what is fibreglass?

Fibreglass (UK) is a common type of fibre-reinforced plastic using glass fibre. The fibres may be randomly arranged, flattened into a sheet (called a chopped strand mat), or woven into a fabric. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinylester—or a thermoplastic.

Cheaper and more flexible than carbon fibre, it is stronger than many metals by weight, is non-magnetic, non-conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, orthopaedic casts, surfboards, and external door skins. Fibreglass covers are also widely used in the water-treatment industry to help control odours.

Why fibreglass is a bad choice

Firstly it is regarded as a danger to human health. It is often seen as carcinogenic and can irritate the eyes, skin, and the respiratory system. Though its thermal qualities are good, it does need a vapour barrier on the inside of every room.  You should use, for example, insulation blankets with an aluminium coating and seal the seams with matching tape. Otherwise, fibreglass can get damp and soiled, reducing its thermal impact.

Case studies performed by the BLF state that fibreglass leads to nasty health issues, like emphysema and bronchitis.

What do you recommend instead?

A far better choice than fibreglass is Icynene Sprayfoam Insulation. It does not slump or sag. It is environmentally friendlier than fibreglass.

It is also non-irritant, airtight and hygienic: unlike many other spray foam insulations Icynene is totally inert, odourless and produces no harmful emissions after installation. It expands in volume by up to 100 times after spraying, pushing its way into cracks and voids to form a complete seal to surfaces and cavities.

Want to know more about how we can help you prepare for colder months ahead?

Contact us today.