Frequently Asked Questions

Earthwool® glasswool is manufactured by Knauf Insulation, one of the world's largest insulation manufacturers, with over 40 factories supplying over 50 countries. Knauf Insulation is part of the Knauf Group, a German family owned business. More information can be found at

In order to keep pricing as competitive as possible, and reduce any chance of damage during shipment, Earthwool® glasswool cannot be ordered in individual packs, and the area calculator will automatically round this up to the nearest MasterBag. MasterBags typically contain 4, 5, 6 or 8 packs depending on the product. If you have excess ceiling product left, we recommend that you add a double layer firstly over the bedrooms and then living areas to maximise the comfort of the home. Wall products can also be installed in Ceilings, however Ceiling products should not be installed in walls.

Orders will be delivered directly to your door within 2-3 business days, anywhere in New Zealand.

Earthwool® glasswool insulation is non-combustible and complies with New Zealand Building Code Regulations (tested to AS 1530.1). Earthwool® glasswool cannot conduct electricity. Polystyrene products, including Climafoam XPS, must not come into direct contact with electrical cabling.
Although there are designated Acoustic products for specific applications, all Earthwool® glasswool products will provide some acoustic performance, as glasswool insulation comes with inherent sound absorbing properties.
No. Earthwool® glasswool insulation has been tested to show that it will not sustain vermin or attract insects.
The Earthwool® glasswool wall products come in a range of R-Values and densities. For example in 90mm walls, the range starts at R-2.2, which provides economical energy saving and acoustic performance, and goes right up to R-2.8, which provides ultimate acoustic performance and energy savings.
Earthwool® glasswool uses a combination of new technologies, which make the product more comfortable to handle. Firstly, Knauf Insulation’s proprietary fiberisation process creates longer strands resulting in less ‘ends’, to reduce mechanical irritation. Secondly, Knauf Insulation’s patented ECOSE® Technology results in a much softer, less ‘crunchy’ and less dusty insulation product compared to traditional glasswool products made using formaldehyde.
The distinctive brown colour of Earthwool® glasswool results from ECOSE® Technology. This natural binding process leads to a natural shade of earthy brown – free from dye or colourants. This is a result of five years of intensive research and development, as part of our commitment to being at the forefront of sustainability. In some cases, if Earthwool® glasswool is exposed to UV radiation, it may result in a white bleaching effect, however product performance is not diminished.
ECOSE® Technology is more sustainable because it uses a natural resin, which is less energy intensive than traditional formaldehyde binders. With ECOSE® Technology, rapidly renewable, organic materials replace the traditional petro-based chemicals used in standard insulation binders to create more advanced and sustainable products. ECOSE® Technology is formaldehyde free.

Earthwool® glasswool products have undergone a comprehensive and rigorous evaluation to determine their environmental effects and acceptability in use, and indicate that products with ECOSE® Technology improve on the already excellent performance of conventional glasswool products.

Earthwool® glasswool carries BRANZ Appraisals to provide assurance it is fit for purpose and complies with New Zealand Building Code regulations.

Earthwool® glasswool insulation is certified by Eurofins Gold as an ‘outstanding material’, according to the VOC (Volatile Organic Compounds) Indoor Air Quality emissions regulations.

Earthwool® glasswool was awarded Eurofins Scientific’s first Indoor Air Comfort Gold Standard certificate as part of the Eurofins Air Comfort Gold standard testing and certification programme.

We are happy to review plans and provide an indication of the product and quantities you may require for your project. However, the final quantities and amounts order by you remain your decision and unfortunately we are not able to accept returns. We suggest ordering slightly less than you may need and then order the final amounts once you have started your project if unsure.
Earthwool® glasswool ceiling, wall and acoustic ranges carry a 50 year Warranty. Underfloor products carry a 15 year Warranty.