Knauf Earthwool Glasswool Insulation Batts for Walls and Ceilings

What is Knauf Earthwool Insulation?

Knauf Earthwool insulation, often known simply as “Earthwool Insulation” is one of the most popular brands of insulation available in New Zealand. Using revolutionary technology, Knauf has pioneered a completely new way of manufacturing glasswool insulation, and the result is a product which out-performed all its competitors on several key fronts. While some aspects  of Knauf Earthwool are slightly difficult to analyse and compare with other glasswool products, there are 3 features where this German brand has clearly stood out, and which can take most of the credit for Knauf Insulation’s continuing growing popularity both here in New Zealand and abroad.

(1) Super Soft & Low Itch Glasswool Insulation

For decades, insulation has been synonymous with pricking glass fibres and irritating itch. Knauf Earthwool is spun from much longer and thinner fibres, resulting in less “ends” to rub against your skin and cause irritation. It also uses an ecofriendly binder, and contains zero formaldehyde, something which was practically unheard of in the past.  If you stick your hand into a bag of Earthwool, you’d be forgiven for thinking that it was anything but glasswool! So is Earthwool completely itch free? If you wear a short sleeve shirt and no gloves, and work for a whole day cutting and installing Knauf Earthwool, you can expect to experience some slight itching on your wrists. However this has nothing to do with chemicals, and a rinse under cold water will quickly resolve this.

(2) Odourless (No Smell)

The pungent smell of the average glasswool insulation… those who have worked with it know what it is. Knauf Earthwool has, practically speaking, no smell! This has provided welcome relief both for commercial insulation contractors, as well as DIY installers who have decided to install the insulation themselves.

(3) Compression Packed for Ease of Handling

Earthwool Insulation is compression packed into individual bags, which are in turn compression packed into larger packs known as “MasterBags.” Depending on the R-Value and the width of the insulation, one MasterBag will contain between 4 and 6 individual bags. This effective compressing of the insulation means that less storage space is required, and also keeps the transport and delivery costs to the absolute minimum.

When you split open a bag of Earthwool, the individual insulation segments quickly expand to their specified thickness. You’ll be amazed at how much insulation fits into a single bag!

Buy Knauf Insulation Online!

If you’re not sure how much Earthwool Insulation you need, jump across to our Insulation Calculator page and scroll to the bottom, where there are clear step-by-step instructions for measuring up all areas of your house, as well as calculating how many square metres of insulation you need.

Below is a sample of some of our most popular Earthwool Insulation Products, with information about the R-Value, dimensions, and the price including GST.

To view a full list of R-Values and options available for any of these products, or to place an order for any of these products, simply click on the product image directly below the table.

Earthwool Ceiling Insulation

Description R-ValueThicknessWidthm2 in one MasterBagCost inc. GST
Earthwool Ceiling RollR3.6150mm1200mm50.4$597
Earthwool Ceiling SegmentsR3.6175mm430mm52.3$475
Earthwool Ceiling SegmentsR4.1195mm430mm44.9$449
Earthwool Ceiling SegmentsR5.2210mm430mm27.9$400

Earthwool Wall Insulation

R-ValueThicknessWidthm2 in one MasterBagCost inc. GST

Earthwool Underfloor Insulation

R-ValueThicknessWidthm2 in one MasterBagCost inc. GST

Earthwool Acoustic Sound Insulation

R-ValueDensityThicknessWidthm2 in one MasterbagCost inc. GST

Best Way to Use up Left-Over Insulation

It’s not uncommon to find at the end of your home insulation project, that you‘ll have a few loose pieces, or even some left-over single bags.

The great thing with thermal insulation such as Knauf Earthwool is that in most homes, it’s possible to use up any leftover insulation bags in other areas of the home – in particular the ceiling or roof space.

The R-Value of thermal insulation corresponds quite closely to the thickness of the insulation material. This means that you can significantly increase the R-Value for example in your roof space, by topping it up with any leftover insulation.  Topping or “doubling” up is completely safe, and there is nothing stopping you from e.g. adding a layer of wall insulation on top of ceiling insulation.

For example: let’s assume you’ve installed R3.6 Earthwool Ceiling Insulation Segments in your 110m2 roof (nothing left over) but you have 30m2 of R2.4 wall insulation left over. By installing the left over wall insulation on top of the ceiling insulation, you will effectively be increasing the performance R-value of the doubled up area (which would now be 265mm thick) to more than R6.0.

Is it worth doubling up with Earthwool under the floor?

It is usually not practical to install regular Earthwool wall or ceiling insulation under an exposed floor. In addition to being difficult to install, eventually the wind and weather will start having a visible effect on this type of insulation. Also, consider the fact that underfloors don’t benefit from a very high R-value in the same way as ceiling insulation does – there’s a reason why the recommended R-Value for underfloors is always much lower than for ceilings.

Below is a quick overview of effective ways you can use up any leftover Earthwool insulation, while at the same time increasing the performance R-Value of your home. This example assumes that it is a new house being built or renovated, and that both internal and external wall cavities are accessible.

Left over Earthwool insulation typeRecommended use
Ceiling insulationTop up existing ceiling insulation, especially above living areas and bedrooms.
Wall insulation (External)As above, or else install in the internal walls
Underfloor insulationTop up existing ceiling insulation, or possible install as a double layer under the floor

Need help working out the best option?

If you’re unsure as to how to put any left-over insulation to the best use, feel free to send us an email following your order confirmation, detailing the dimensions of all the accessible wall, ceiling and underfloor areas. Make sure you also include your order number.

A helpful team member will review this in conjunction with your insulation order, and provide you with a recommendation.

Installing Earthwool Underfloor Insulation

Some Technical info

Regardless of application, density, R-Value and thickness, all Knauf Earthwool insulation are essentially made from the same materials.

Here are some of the top features and benefits:

  • Soft, low itch glasswool
  • Rot-proof
  • Odourless
  • Non-hydroscopic (doesn’t absorb airborne moisture)
  • Doesn’t sustain vermin
  • Chemically neutral
  • Backed by a 50 year warranty.

For more detailed technical information about Knauf Insulation, please visit the manufacturer’s website – 

Where is Knauf Earthwool Insulation manufactured?

Earthwool insulation is produced in manufacturing facilities across several continents. Until recently, most Earthwool Insulation sold in New Zealand originated from the United Kingdom; however this is likely to change following the completion of the new Knauf manufacturing facility being built in Malaysia, which according to Knauf, is on track to be completed in 2020. The new insulation plant is located in Johor Bahru, just north of Singapore.

Check out Knauf’s promotional video regarding their new insulation factory.