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Mammoth Polyester Insulation for Ceilings, Walls, Floors

Mammoth polyester insulation is made from a low denier hollow core conjugate-helical synthetic fibre. It closely replicates the insulating performance of fine wool. Mammoth is also made from a high recycled content (reconstituted fibre) which are bonded together using heat not glue, so unlike other products, there are no components which can break down.

Life-Time High Performance

BRANZ Appraised Manufacturers Brochure

As appraised by BRANZ, the Mammoth product range performs in accordance with the building code to last for 50 years plus.

Environmentally Safe and User Friendly

  • All Mammoth products contain a high level of recycled polyester fibre made from plastic bottles.
  • Mammoth will absorb noise to create a quieter environment
  • Mammoth is manufactured in New Zealand
  • Mammoth will perform well if installed as per NZS 4246 for at least 50 years
  • Mammoth is resistant to vermin attack as polyester fibres are not a food source 

Mammoth products are classified by OSH as both non-irritant and non-toxic. Mammoth is 100% safe for everyone, including asthma sufferers. Some traditional insulation products use formaldehyde as the binding glue, but Mammoth is made from fibres bonded by heat.

Best value for money

Long-lasting high-performance insulation can save you money in heating and cooling bills and protect your family's health. The up-front cost of premium insulation is well worth the investment.

Insulation must have the ability to be installed so that it performs effectively over it's life time. Once the internal lining goes up, no one knows what's happening behind it. Yet your home will be occupied for decades ahead and you will want to be warm for all of that time.

Negawatt has chosen Mammoth as its preferred bulk insulation products supplier who we have worked very closely with since there inception. Mammoth is simply the highest performing and most cost-effective available and will hold its insulation values throughout its life. It does not slump or subside over time. Mammoth polyester insulation is completely inert and does not incorporate any added chemicals. No protective clothing or respiratory equipment is required whilst being installed.

48% Higher Thermal Performance With - Overlaid Ceiling Insulation

The way insulation is installed impacts greatly on the performance achieved. Once installed the building component is termed as having a system R-value. The product R-Value as stated on the packaging or information pamphlet of the insulation is not necessarily the system R-Value achieved.

Common Installation

Material R-value R3.2
System R-value R2.3
Common ceiling insulating materials are installed in between the ceiling joists (biscuit installation). The thermal bridging of the timber joists then reduces thermal performance of the insulation by up to 25%. Poor installation practice (e.g. with small gaps around the edges) can cut down another 50% of the performance.

Overlaid Installation

Material R-value R3.2
System R-value R3.4
NOVAtherm Polyester Insulation comes in rolls, which allows for installing the ceiling insulation overlaid rather than put between the ceiling joists and thus achieving 45% higher thermal performance.The R-Value comparison of biscuit and overlay installation techniques has been confirmed by BRANZ Appraisal 430 (2002) for NOVAtherm Polyester Insulation.

Features and Benefits


  • Non-toxic
  • Non-fibreglass
  • Biologically inert, No chemicals
  • Non-aqueous ( hydrophobic )
  • 50 years nominal lifetime
  • BRANZ tested T177
  • Zero Fire Rating
  • ISO manufactured
  • Supplied in rolls not batts
  • Tears easily across width
  • Maintains loft over time


  • Clean installation
  • No protective wear needed for installation
  • No health risk
  • Does not absorb water
  • Expected to be exceeded
  • Performance Certified
  • Meets fire standard NZS 4222 - 1992
  • Product consistency
  • Easier, faster installation - reduced installation labour cost
  • Reduced installation labour cost
  • No performance degradation

Poorly fitted wall insulation with small gaps cuts thermal performance by up to 50%. Read here

Wall Insulation And Its Importance

Now you have insulated your ceiling and floor your biggest heat loss is your walls. New technology is now available to make your walls feel and behave like never before. Read here.


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Wellington Mail Centre, NZ

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