FAQs

Building regulations

Why are there parts of my house with no or little insulation?

The levels of insulation required were then increased in 2007 and again in 2021, so homes built between 1978 and 2021 could also benefit from additional insulation being installed. If you’re unsure about the levels or condition of insulation in your home you can arrange an inspection of your property by an approved insulation installer. We recommend purchasing the highest R-Value that your budget allows.

For the latest on the insulation requirements for the Building Code click here.

Glasswool insulation

What are the health effects of glasswool insulation? Is glasswool safe?

Glasswool has been used globally for over 70 years and over 50 years of research has not found any cause and effect link between glasswool insulation and long term health problems. When using glasswool in Australia look for the EUCEB and or FBS-1 logo for quality assurance.

Some types of glasswool insulation are also made without using a phenol formaldehyde binder, making them even safer to use in your home.

Are rodents attracted to glasswool insulation?

No. Because glasswool insulation is made using glass it will not attract or provide a food source for rodents or insects.

Packaging

Is the packaging for your insulation products recyclable?

Yes, the majority of our product packaging is low-density polyethylene (LDPE4) plastic, which is fully recyclable. All our packaging that is made using LDPE4 will include the following symbol:

Are the MasterBags recyclable?

Yes, all our MasterBags are made of 100% polypropylene (PP), which is recycling group number 5.

What else is Knauf Insulation doing to reduce plastic waste?

Knauf Insulation has been reducing the amount of plastic we use for a number of years.

We've made our overwraps (film) thinner and ensured our packaging is 'machine direction orientated', resulting in less elasticity whilst still effectively compressing and protecting our products.

We use the most advanced packaging compression, achieving a maximum of 9:1 compression rate. This means we have more insulation per pack and more insulation can be loaded on each truck, resulting in less trucks on the roads, and less storage and handling for our customers. However, to achieve this level of compression, we have to use robust plastics that can handle the process. Using LDPE4 means that the majority of our packaging can be recycled whilst still being able to achieve maximum compression, ensuring we are sustainable as a company.

We have also sought to reduce unused plastics, off cuts and waste which has resulted in less plastic being involved in our manufacturing and packaging process.

Residential Tenancies Amendment FAQ's

What’s changing?

In July 2015, the New Zealand Government announced the introduction of a Residential Tenancies Amendment (RTA) Bill. This move follows trials based on a broad package of ‘Warrant of Fitness’ standards. It was deemed that a full Warrant of Fitness would be expensive both to implement and administer. Therefore, the RTA is focussed on the essentials, which have proven benefits to the health and comfort of tenants. The two key measures that will be introduced are smoke alarms and insulation.

Why Insulate?

What are the benefits of insulating my home?

Glasswool insulation has many benefits such as:

1. Making your home warmer in the winter and cooler in the summer.
2. Making your home more energy efficient – this means making savings on your energy bills.
3. Reducing the transfer of unwanted noise from outside and between adjoining rooms.

I have solar PV system - do I need to insulate my home too?

Yes. By combining insulation, which reduces energy use, with a Solar PV system – homes can get even better value from their investment.

Adding insulation can reduce the up-front costs for the Solar PV system and can also improve the payback period for the system.

Ceiling insulation

How much will ceiling insulation cost?

The cost depends on the size of your house and whether you have existing insulation. For example, in an un-insulated ceiling, buying the product that will generally bring you up to the minimum Building Code Standard will cost only around $8.30 per square metre for most of the North Island, and $8.80 per square metre for the South Island (and central plateau). Alternatively, if you already have insulation and want to ‘top-up’ then you could purchase an R-2.2 handy roll, which will cost around $6.33 per square metre. Depending on the size of your home, it can take around three years to realise the payback* through savings on your energy bill.

We advise that you aim for the highest R-Value your budget will allow.

How much ceiling insulation do I need?

This will vary on the type of building you have and where you live in Australia, but generally to meet the current minimum Building Code requirements you need at least R-3.2 ceiling insulation in most of the North Island, and R-3.6 in the central plateau and the South Island.

We advise that you aim for the highest R-Value your budget will allow.

I already have some insulation in my ceiling; do I need to take this out first?

The existing insulation may not have much insulation value, but every little bit counts and there’s no point wasting what you already have. If the existing insulation is level with the ceiling joists, you can add the new layer of insulation over the top at right angles to the original layer – this creates a continuous layer of insulation and helps prevent thermal bridging through the joists.

We advise that you aim for the highest R-Value your budget will allow.

I use my ceiling for storage. Do I need to clear it out if I am having the insulation professionally installed?

Yes, you will need to clear the ceiling of any stored objects before the insulation is installed. And who knows, you may even find some valuable, hidden treasures too!

I want to use my ceiling for storage, how can I do that if it is insulated?

You or your installer can also lay insulation boards called ClimaFoam® along with an 18mm layer of chipboard deck on top to provide storage space. These insulation boards are made from extruded polystyrene and are designed to be placed on top of the ceiling joists instead of the glasswool insulation. ClimaFoam® is a perfect solution for storage space in the ceiling space as they have high compressive strength and provide great thermal performance. You will need a ceiling hatch which is minimum 600mm wide. Having R-2.6 glasswool insulation installed between the joists plus a layer of 50mm ClimaFoam® board with a chipboard deck laid top and bottom gives the same thermal performance as installing R-4.1 glasswool insulation and will eliminate most thermal bridges.

thermal bridging

How long does it take professionals to install ceiling insulation?

Generally it should take half a day for a team of installers to insulate a ceiling.

How long would it take me to insulate my ceiling?

Please read more detailed information about installing ceiling insulation before carrying out any work. Having read the installation instructions it is important that you and your installation partner work at your own pace to ensure the installation is done safely and effectively, avoid being in the ceiling space during the hottest part of the day.

Make sure you switch off the electricity supply at the mains before entering the ceiling space.

How can I insulate my skillion roof?

Installing insulation in a skillion roof is similar to installing insulation in a wall and will noticeably reduce the amount of heat transferred through your skillion roof. The most common products are R-3.2 105mm Skillion or R-3.6 150mm Loft Roll, or sometimes people use high density wall insulation products such as R-2.6 or R-2.8 wall segments. You want to maintain a 25mm air-gap above the insulation to allow for ventilation. For example if you have 140mm joists, you would want to use R-3.2 105mm. If you had 190mm joists, the best option would be R-3.6 150mm.

Refer to the manufacturer’s instructions.

Will glasswool insulation make my home quieter?

Glasswool insulation has both thermal and acoustic properties and will help reduce the transmission of sound from outside into your home. It can also reduce noise transfer between adjoining rooms when installed in internal partitions.

Can I install ceiling insulation myself?

Yes! Watch a video on how to install ceiling insulation and make sure you read our detailed installation and health and safety instructions, before carrying out any work. If you do not have the time or the confidence to do it yourself, you can arrange to have the insulation professionally installed.

Wall insulation

How much will wall insulation cost?

The cost depends on the size of your house and whether you have existing insulation. For example, for un-insulated walls, buying the product that will generally bring you up to the minimum Building Code Standard will cost around $6.40 per square metre for most of the North Island (R-2.2), or $12.00 per square metre for the central plateau and the South Island. Wall insulation for 90mm framing goes up to R-2.8, and for 140mm framing up to R-4.1.

We advise that you aim for the highest R-Value your budget will allow.

How is wall insulation installed?

There are two ways you can retrofit wall insulation – from the outside or from the inside.

For more information, watch our wall insulation install video.

Some older houses are also suitable candidates for blow-in insulation (Jet Stream® MAX) glasswool insulation is injected into the cavity from holes in the plasterboard, which are then repaired. Making it an ideal solution for increasing the energy efficiency of older homes where it is impossible to install segments.

Will adding glasswool insulation make my home quieter?

Glasswool insulation has both thermal and acoustic properties and will help reduce the transmission of sound from outside into your home. It can also reduce noise transfer between adjoining rooms when installed in internal partitions.

Can I add insulation to my internal walls to make my home quieter?

Yes. Adding insulation to your internal walls will help reduce the transmission of sound between rooms. For best results you should add insulation around your entertainment room, kitchen, laundry and bathrooms. This can be installed at the time of building, or retrofitted later using blow-in insulation.

Can I install wall insulation myself?

Yes! Watch a video on how to install wall insulation and make sure you read our detailed installation and health and safety instructions, before carrying out any work. If you do not have the time or the confidence to do it yourself, you can arrange to have the insulation professionally installed.