Save Money with Insulation – Which is Best Part II

Save Money by Insulating Your Home

Which Insulation is Best – Part II

Following on from previous blogs where I discussed the pros and cons of denim and wool insulation, today I look at Cellulose and Fibreglass, and some new technologies as well.

Cellulose

Cellulose used to be made from all sorts of materials, but nowadays it’s mostly made from recycled newspaper which is shredded, which makes its manufacturing method quite eco-friendly.   It fits snugly around pipes and wiring, better than batts (e.g. fibreglass and denim) but not as well as spray foam.  Some versions have a higher R-value than fibreglass.  It’s approximately cost-comparable to fibreglass.  It doesn’t need protective clothing to handle, but the installer should wear a mask due to the dust at that time.

Cellulose Insulation has four major types:

Dry Cellulose (Loose Fill): Used for retro-fitting existing houses.  It’s not as dense as the wet spray, and settlement can occur; therefore it’s not as efficient.

Spray Applied Cellulose (Wet Spray) is used in new wall construction.  Water, chlorine and adhesive are added to the newspaper.  As is the case with all spray insulation, it fits more snugly so the seal is better and thus more efficient.  However, some versions utilize an environmentally harmful blowing agent, such as Enovate HFC.

Stabilized Cellulose: Used for attic/roof insulation.  A very small amount of water is added, thus keeping the weight low – an important factor for avoiding sag.

Low Dust Cellulose: is appropriate in homes where people are sensitive to newsprint or paper dust (though new dust will not be created after installation).  Oil or a similar material is added.   Most cellulose is quite low-dust as standard; this is an additional option.

Pros: Around 80 – 85 percent of its content is recycled material, one of the highest in the insulation industry, the manufacturing process doesn’t use a lot of energy, and it saves paper going to landfills.  Thus its ‘eco-cred’ is quite high.  Cellulose is relatively cheap to purchase and easy to install.   It’s denser than fibreglass and thus provides better sound protection too.   Most versions achieve the top fire rating, and are pest and mould resistant.  Tests have shown 20-30 percent less energy is needed when cellulose is used rather than fibreglass.  Cellulose does not need an additional vapour barrier (normally made of plastic).  Although it uses adhesive, it is not formaldehyde-based (unlike with most fibreglass).

Cons:   There have been some studies on cellulose in connection with electrical wiring which can produce extreme heat and cause fire because the cellulose fits snugly and is made from paper (albeit with fire retardant).   Dust is blown into the house through inadequate seals around fixtures or minute holes.  Some versions utilize an environmentally harmful blowing agent.  Most building codes require a vapour barrier, and it can be hard to convince some cities that one is not required for cellulose. In this case, an appeal (usually a quick process) may be necessary.  You need to allow for drying time before work can progress further.

Fibreglass

Fibreglass (Glass Wool) is made up of tiny fibres of glass, made from silica (sand).  It is very commonly used as it is relatively cheap.  However, its ‘eco-cred’ is not great – it’s manufactured in very high temperature furnaces which require a great deal of energy.  Nowadays some fibreglass is made from recycled glass, which helps its environmental footprint.   It requires protective clothing for installation, and is generally not considered safe to be exposed to.  Chemicals are added to make it fire and pest resistant.  It is sold in rolls and batts, and also as a blow-in.

Fibreglass became popular once it was discovered that asbestos was toxic and needed to be removed from houses.  Ironically, fibreglass is also a silicate fibre and has very similar properties to asbestos.  There is some concern that fibreglass may also be a carcinogen, but different testing bodies have differing views.

Pros:  It is one of the cheapest insulation options.  It is readily available and easy to install.

Cons:  Due to fire risks, some countries have said it cannot be placed next to electric boxes and down-lights – this reduces its insulating effectiveness. There are health concerns.  It may contain formaldehyde.

Rigid Polystyrene

Polystyrene is made from petroleum and is a kind of plastic.  Recycling rates are low and plastic isn’t bio-degradable, causing problems in water systems and with animals and birds.  As such, it is not eco-friendly.  Polystyrene is also used in insulting concrete forms.

Pros:  Polystyrene has the highest R-value and is relatively cheap if the R-value is taken into consideration.  It is easy to cut so wiring can run through or near it.  No protective clothing is required during installation.  It is very easy to install.  It’s light.

Cons: It is definitely not eco-friendly.  The flame retardants used (commonly decaBDE) have known health issues.

Straw Bales

These were used for centuries as insulation, and if there isn’t a lot of transport involved, they can be very cost-effective and eco-friendly.  They take up quite a lot of space (they’re thick) but very effective.  They’re not the best option if you live close to the sea, and you need to make sure rain doesn’t get into them.

New Materials to Watch…….

There are a lot of promising new materials being used for insulation such as Nanogel and Icyene.  They are high-tech and non-organic, yet their special qualities permit new developments in insulation such as spray-in-place quick fixes, and translucent insulating walls.

Aerogel (a registered brand of Aerogel is Nanogel) is a form of “frozen silica smoke” – made of a special type of super-porous silicon foam that is 99% air. It’s incredibly strong, incredibly insulating and incredibly light.  The picture shows it supporting a brick – pretty clever for something made mostly of air!

However, because it’s made of silica, it has the same health issues as asbestos and fibreglass.  So it’s sold pre-packaged into polycarbonate or fiberglass panels under trade names like Kalwall and Supersky Systems.

The big deal with this form of insulation is that it is translucent i.e. it allows daylight into your building, while still insulating you.  And products like Duo-Gard  include coloured LED lighting.  However, the effects of nano-particles on the human body and the environment are still unknown.

Next: Find out about R-Value,  Denim and Wool insulation    and   Which insulation is EcoExpert’s favourite?

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Photo Credits:  Cellulose Insulation: Materialproject.org.  Aerogel: NASA.