Category Archives: General Knowledge

Soundproofing your home

Soundproofing your home? We look at the acoustic properties for common insulation products.

What insulation is right for soundproofing your home?

If you’re looking at soundproofing your home then insulating your walls is a great starting point. The main reason you get a lot of noise transfer through your home is that for most New Zealand homes, there’s little to no insulation in the walls. This means that all you have separating one room from another is a thin sheet of plasterboard on either side of the wall.

Insulating your walls helps fill the air gap and reduces noise transfer inside the home. Not all insulation products are created equal however and choosing the right product for your walls will make a big impact on the level of noise reduction.

In this article we look at several types of insulation products available in New Zealand and discuss the advantages and disadvantages when it comes to soundproofing your home.


Batts are usually made of glass wool (also known as fiberglass) insulation. This type of insulation has been used in the New Zealand market for over 50 years and is generally known as an effective insulation product. It’s made from recycled glass and comes in a variety of thicknesses and sizes.

Batts typically comes in a roll that has a fixed width and you cut segments from this into the sizes you need for your walls or roof cavity. These segments are then placed in-between your timber framing.

Soundproofing with a batts style product can be a little challenging. Even with the best installation, there are often small gaps left around the corners and edges of the batts. This means that air and noise penetrate the walls. Soundproofing a house requires no gaps in your insulation barrier to be effective at eliminating noise transfer. For this reason, batts are not our preferred solution for soundproofing your home.

Foam Insulation

Sprayed polyurethane foam insulation has been widely used over the last few decades in New Zealand homes. It’s effective at completely filling your wall and helps to curb sound resonance however it’s not as effective as other insulation products that are denser.

While foam insulation will help seal a cavity and provides an effective thermal barrier, the compound is not effective at absorbing sound and therefore not a good choice for soundproofing your home.

The recent decline in popularity of foam insulation has also been driven by recent studies which show that spray foam can lead to damage of your timber framing, the material may actually shrink overview and there are several potential health issues caused through the chemicals used in the insulation.

Loose Fill Insulation

Many insulation companies these days are using a loose-fill glass wool product. CosyWall Insulation is a good example of common loose-fill insulation and has been widely used throughout New Zealand homes for the past 20 years. Insulation is blown into your wall cavities and doesn’t require the removal of the wall linings. The process is fairly simple and can be done from either the inside or the outside of your walls.

The materials in loose-fill insulation are similar to those found in batts.  It’s blown at such a high density that it fills up all the space in your walls. This doesn’t leave any gaps for air or noise to penetrate. Blown Insulation is a great product that provides both thermal and acoustic insulation properties. It’s our preferred choice when soundproofing your home.

Do you need some more help?

If you’re wanting to fully soundproof your home, insulation is only one part of the puzzle. Insulation will help in soundproofing but should be used in combination with other products and materials for the best results.

The team at CosyWall Insulation would love to chat to you about insulating your home. If you have questions about acoustic insulation or soundproofing your home contact us and we’d be happy to help you further.

Condensation issues in your home

Condensation issues in your home and how to fix them

If you’ve been living in your home a little while, you may have noticed that parts of your home walls can get very damp. This is usually because of condensation issues in your home and is usually a good indication that the walls of your home are not well insulated. If damp or wet walls aren’t addressed quickly, this can lead to mould developing inside the home which can damage your walls and furniture, and seriously affect the health and wellbeing of your family. In this article, we’re going to look at what causes condensation and steps you can take to deal with the issue.

What causes condensation in my home?

Simply, condensation starts to occur when warm air and cold air meet. It can also occur when there’s a lot of humidity in the air and not enough ventilation. It is most evident in the winter and is usually a result of your efforts to keep your house warm. Everyday activities such as cooking, showering, and drying clothes can also release moisture into the air which can also lead to a build-up of condensation in the home.

For older New Zealand homes, there may be many breaks in your home’s thermal barrier which allows air in and out of your home. When your inside warm air starts mixing with the outside cold air it cools down quickly, releasing the water molecules from the air. These turn into liquid droplets that attach themselves to cold surfaces such as your walls and develop into condensation.

Condensation tends to be less of an issue during the summer months as you’re always opening the windows and doors to let fresh air in, and this helps to keep the home ventilated. In the winter months, you typically keep all the windows and doors closed so the cold air doesn’t come inside and if the house isn’t well ventilated, condensation can quickly develop. While most houses have extractor fans in the bathrooms, these small fans are usually not enough to keep the entire house ventilated and when the outside air temperature starts to drop, this is when you start to notice the damp and wet walls.

While a little bit of water may not sound like a major issue, if this problem is left unattended, it can create the perfect environment for black mould to grow which can lead to several health issues including respiration problems, skin rashes, and sore or itchy eyes.

What can you do to fix condensation issues in the home?

Luckily, there are some simple steps you can take to ensure close your home’s thermal envelope and fix your condensation problems. The first thing you want to do is prevent the outside air from getting into your home. There could be a number of weak points in your home contributing to this issue including

  • Gaps around the windows and doors in your home
  • Poor insulation in your walls, underfloor or roof
  • Leaks in your roof
  • Damage to your homes cladding
  • Poor ventilation in your home

Clearly if there’s damage to your home and it is not weathertight, these issues need to be immediately addressed. Leaving your home exposed to New Zealand’s harsh climate for extended periods of time can lead to an expensive repair bill and numerous health issues.

You could also invest in better extractor fans and/or a dehumidifier to remove moisture from the air however in most situations the underlying issue related to condensation issues is either poor or a lack of insulation.

Insulating your home is probably the single best thing you can do for your family’s health and wellbeing and in New Zealand, homes usually only have the minimum standards of insulation. When we inspect most homes, we find that there is a little bit of insulation in the roof and under the floor but usually no insulation in the walls. If you think about it, insulation is designed to provide a barrier that keeps the outside air temperature out, and the inside temperature in, and if the walls are not well insulated, all your heating efforts are easily lost through the walls. By insulating your walls, you’re helping to close your home’s thermal envelope and this helps to permanently fix condensation issues in your home.

Insulation products like CosyWall Insulation can be easily blown into the walls of your home without having to remove the linings. It is pumped into the walls through small holes that are patched up after the installation, so you’ll never know the process was done. Additionally, because it’s blown in at such a high density, it will never shrink or slump inside the walls and with a 50-year durability rating, the insulation will last the life of the home.

Talk to the team at CosyWall Insulation today about organising a free home assessment for your property.

Black mould can lead to serious health issues

Health issues caused from Mould

Having mould in your home can be a costly and dangerous problem and can lead to a number of serious health issues. Black mould, also known as Stachybotrys can release spores into the air as it feeds on organic materials common in most houses. These spores if inhaled can lead to a range of mild to series symptoms for your family. You might be curious about what causes black mould to grow in your home anyway? Too much moisture in your home is usually the catalyst and damp or wet walls or condensation build-up on the windows and sills are obvious signs you have a problem.

The most common symptoms of mould are associated with your respiratory response however symptoms may be more severe if you have a mould allergy.

  • Regular coughing or sneezing
  • Sore or itchy eyes
  • Sore throat
  • Skin rashes
  • Chronic fatigue
  • Headaches

If left untreated, prolonged exposure to mould and cause more serious or dangerous health issues. If you’re noticing nausea, vomiting and/or bleeding in the lungs and nose, this is usually a sign that urgent treatment is needed. If you’re seeing any of these indicators, it’s important that you take swift action and approach your medical practitioner immediately.

Serious mould infestations and be very costly to remove and may require a professional. In some situations, renovations of your home may be necessary to replace damaged materials to resolve the problems which is why we recommend taking steps to address the underlying causes of mould quickly.

Treatment for mould health issues

There are several treatments for mould allergies or mould exposure symptoms including nasal sprays, rinses and allergy shots. Antihistamines are also available from most pharmacies which can help your immune response.

If you are experiencing any mould related symptoms, its best to seek advice from your local medical practitioner immediately.

What can I do to remove mould?

If you start noticing mould growing on your walls it’s usually a good indication of high levels of moisture in your home. In New Zealand, this is likely caused by poor insulation and/or ventilation in your home. It may be helpful to have an expert come and do a healthy home assessment to determine any weak points that need addressing.

Mould usually occurs in damp or moist places throughout the home so the usual rooms you’ll start noticing mould growth is in the bathroom and kitchens.

Bathrooms tend to be one of the more common places and the room isn’t well ventilated this will quickly lead to mould growth. Having a good extractor fan in the bathroom is critical to removing moisture from the room.

Likewise, a good extraction system in the kitchen can help remove moisture that is caused by cooking and food preparation.

Another major issue is to do with poor insulation in your walls. Poor insulation can lead to condensation issues or damp walls. This is the perfect environment for mould growth and usually means there is no insulation in the walls. Insulating your walls is probably the best way to control the moisture in your home and using a blown insulation product like CosyWall Insulation is a great way to fix the issue.

CosyWall can easily be blown into your walls from either the inside or outside of the home without having to remove the linings. Once installed, it helps seal your homes thermal envelope and will stabilise the temperature of your home.

Have a look at our video which talks a little bit about how uninsulated walls can lead to the growth of mould in your home.

Talk to an expert

If you think you need some help from an expert feel free to have a chat with one of our CosyWall Insulation team members. They can help you organise a free home assessment and provide you the best solution for your home. Email us on or contact us today to find out more.

Mould growth inside your home

What Causes Black Mould

Mould is a form of fungus which can be found in black, white, orange, green or purple. They are small organisms which can live almost anywhere indoors, or outdoors and reproduces lightweight spores that travel through the air.

Most of us are exposed to mould everyday however it’s usually harmless in small amounts however when it lands on a damp spot in your home, it can start to grow and this can lead to serious health issues.

Health issues caused by mould

Many people are unaware that black mould can cause health issues. When mould is found high levels inside your home, it can cause allergies, lead to asthma attacks in some cases even lead to infections in some people. The deadliest mould is called Stachybotrys, which is more commonly referred to as “black mould”. This is one of the most dangerous types of mould and can cause flu-like symptoms, diarrhea, headaches, memory loss and severe respiratory damage.

How does black mould grow?

For black mould to grow indoors, it needs moisture and food. Black mould tends to thrive in warm and frequently moist environments such as your kitchens and bathrooms. Moisture is a key factor influencing mould growth indoors and controlling indoor moisture can dramatically help to limit its growth. Moisture control is crucial as mould can begin to grow indoors in as short as 24 to 48 hours when conditions are right. A great way to control moisture in your home is to fully insulate your home, ensuring its thermal envelope is sealed. While most people have roof and floor insulation, typical New Zealand houses lack wall insulation, and uninsulated walls can easily let moisture into your home.

Black mould does not need a lot of water to grow. A little condensation, in a bathroom or around your windows can be enough for mould to start growing. Common sites for indoor mould growth include bathroom tiles and grout, the corners of your walls, areas around windows, near leaky plumbing, and around sinks. Most common causes of moisture in your home include roof leaks, condensation due to high humidity, poor insulation, cold spots in a building or leaks in plumbing fixtures.

Besides moisture, mould also needs nutrients, or food, to grow. Mould can grow on virtually any organic substance. Most buildings are full of organic materials that mould can use as food, including many building materials and household furnishings.

What can you do to avoid mould growth in your home?

New Zealand’s widely vary between the summer and winter months making it difficult to control moisture and causing condensation issues.

A great way to control moisture in your home is to fully insulate your home, ensuring its thermal envelope is sealed. While most people have roof and floor insulation, typical New Zealand houses lack wall insulation, and uninsulated walls can easily let moisture into your home.

CosyWall Insulation is an excellent insulation product that can be installed in virtually any New Zealand home. It’s blown through small holes into the walls from either the inside or the outside of the home which are patched up following the installation, so you’ll never know the process was done. You will instantly notice a much more stable inside temperature which among the many other benefits, will help you control the moisture inside the home which will help prevent black mould in the future.

Contact the team at CosyWall Insulation today for a free assessment of your home.

Insulation Association supports call for new Grants to protect vulnerable New Zealanders from COVID-19

The Insulation Association of New Zealand (IAONZ) has grave concerns for New Zealanders in poor housing heading into winter living in cold damp homes. Additionally, the potential for significant insulation sector job losses may result in less houses being insulated this year.
While the Residential Tenancy Act and the Healthy Homes Guarantee’s Act focuses on rental properties, there is no Government focus on what will happen to privately owned homes if the owners are suffering income reduction or job loss.

IAONZ President, Wade Maurice states “Insulation for New Zealand is a proven life saver helping to keep houses warm and reduce expensive power bills during winter. We are calling on the Government to make Insulation grants available for all homes owned by New Zealanders who are affected by COVID-19 job losses or income reduction”

Mr Maurice continues “The Government is seeking “Shovel ready” projects to assist the country back out of lock-down. The Association cannot think of a project with such proven benefit than to insulate private houses for those who are going to be affected by the economic fall-out. To have a large number of people in homes that are cold and damp continues to create an ongoing issue for further illness and for COVID-19 to further spread.”

Otago University public health professor Philippa Howden-Chapman said people living in cold, damp and overcrowded homes were more vulnerable to Covid-19.1

640,000 homes need insulation

The latest BRANZ House Condition Survey2 states that the number of private homes that could benefit from retrofitting insulation in the ceiling and / or subfloor totals approx. 640,000 homes.

The Government should be considering a “Shovel ready” grant which provides more warmer drier homes, assisting with reducing further illness or repeat flare-ups of COVID-19 and in turn increases employment in the sector.

Mr Maurice continues; “The last thing New Zealand needs is bouncing between Alert levels. While the Government is right to be focusing on business and community spread of Covid-19, we need to look further into reducing the source in the home. Hearing that Covid-19 could survive for between nine and 28 days on plastic or hard surfaces at 4C which can occur in uninsulated homes is troubling, so let’s get New Zealand homes warm and healthy sooner rather than later.”

For more information please contact:

Wade Maurice
President IAONZ
021 375 870

Richard Arkinstall
Executive Officer
027 288 3770

4 signs you should replace your home’s insulation.

Insulating your home is one of the best things you can do for your health, wallet, and investment. Just like anything though, it’s vital to ensure that it is up to date and installed correctly, so that you can reap the best benefits of home insulation. There can be serious health and financial consequences if your insulation isn’t performing optimally – if your insulation is old or ineffective, it will literally pay to find out.

Here are 4 signs that it may be time to look into replacing your insulation.

Changing Indoor Temperatures.

If the indoor temperatures of your home are constantly changing, that’s a sign that your insulation should be replaced. Well-insulated homes take a while to respond to outside temperature changes, as good insulation impedes the transmission of heat. If your home responds rapidly to temperature shifts, however, that likely means your insulation has thinned down. You might either need to replace it or add more.

Indoor Drafts

 When parts of your insulation wear down, the winds can exploit your homes new found weakness, and then you get a suction effect where wind pushes its way through the gap and sucks warm air out of the house so the cold can replace it. The draft you feel is this cold air muscling its way in and shoving your warm air out.

Out of control energy bills

 If your energy bills are fluctuating rapidly as the seasons change, that’s a sure fire signal that your insulation is becoming ineffective. If in winter, your heater is working around the clock and in summer your air conditioner is cranking 24/7, then usually your insulation is to blame. Cooling and heating systems are necessary to maintain a consistent level of comfort in your home and add an extra level of control over your house temperature, but they shouldn’t be working overtime.

Wet Insulation

 If the insulation become moist, damp, or sopping wet, there is no salvaging the material. It must be replaced immediately. Blocked vents, a leaky roof, a basement flood, or the absence of vapor barriers can cause crawl space or attic insulation to get wet. Not only can wet insulation grow mould that releases dangerous mycotoxins in to the air, but the moisture causes the insulation to become ineffective. The tiny air pockets that are instrumental in trapping the air and maintaining the temperature are plugged with water, rendering the insulation useless.

Insulation is essential in living comfortably. Having quality, up-to-date insulation will ensure your house feels like a home year round.

If you’re worried about any potential heating or cooling problems, get in touch today. Our technicians are happy to help make sure you have everything you need to stay warm this winter.


Can you have too much insulation?

As hidden as insulation is behind the walls, up in the attic and under the floorboards, its benefits are not so obscure! You probably know by now (especially if you’ve read our blog before) that the right amount of insulation can help reduce energy bills and improve comfort all year round.

The key words there are “right amount.” If your home is not properly insulated or installed, then you’ll have a much harder time reaping the benefits of saving money and staying comfortable. The question of whether “too much of a good thing” crops up when there are concerns of going overboard with sealing a house and potential problems with doing so, such as moisture build-up and mold to polluted indoor air.

A house can definitely be under-insulated but today, let’s dive into the question of whether your home can be over-insulated.

First, let’s start with the basics: how does Insulation work?

During the winter, the air inside the home is warmer than the air outside. The insulation slows down the movement of energy from the warm area to the cold area, creating a thermal barrier that means your heaters or fireplace don’t have to work as hard to keep the home warm. The thicker the insulation, and the lower the U-value, the better this thermal barrier is and so the slower the heat will escape the home.

During a summers day when the temperature may hit 30 degrees, the air outside is generally warmer than the air in the home. With the heating off, the house warms up gradually through the day as the walls and roof absorb the heat of the day. But because the air outside is warmer the thermal barrier created by the insulation will again slow the movement of heat, but in the opposite direction. Warm air in the roof will not be able to penetrate into the home as easily, whilst insulation in the walls will prevent them from warming the home as quickly as well.

What about air quality if the house is too tight?

It is important for your home to have good air quality – poor air quality can be hazardous to health. Not all insulation is created the same. Insulating your walls with vapour resistant insulation, like we do, reduces condensation that is caused when the moisture from daily activities, such as cooking, washing, and bathing gathers on the surface of your walls. It’s an effective way to avoid the harmful effects of moisture in your home.

Insulation is vital for your home

Wherever you live and whatever the type of property, insulation is absolutely vital – especially with spiralling energy costs! And while there are potential risks of over insulating your home if you choose the wrong installer, there’s a much better chance you don’t have enough insulation, particularly if you’ve noticed:

• Higher than normal energy bills (without an increase in usage)
• Drafts or uneven temperatures from room to room
• Unusually warm second floor in your home

Installing Cavity Wall Insulation

It’s vital when upgrading your insulation to get just the right amount and to ensure that it’s properly installed. The team at CosyWall Insulation has you covered in this area. We install the highest quality materials and always ensure you feel confident and comfortable in your newly insulated home.

Get in touch today for a free assessment!

Is all insulation the same?

We’ve mentioned before how insulation helps to reduce energy costs and keeps your home more comfortable. However, insulation comes in many different types, applications and efficiencies. It can be tempting to think that putting in some insulation will be a magic bullet, but it’s actually more complicated than that. Is all insulation the same?

Today, we’re going to look at the different types of insulation and whether they are all created equal.


There are 5 main types:

1. Batting (Fibreglass, Rockwool, Polyester): Batting comes in sheets and rolls to be cut and placed into roof cavities and under floors. It’s difficult to install in walls, except during construction. It can also release inhalant microfibres that cause respiratory issues. Also compresses fairly easily, reducing its effectiveness. It can be installed DIY, but as we’ve said before, there are complications there.

2. Loose-fill (fibreglass and cellulose): Loose-fill is blown into cavities to create a layer that settles. It’s lightweight, so great for unreinforced ceilings and walls, adding insulation but not too much weight. It’s easier to install in tight spaces, especially cavity walls which are notoriously under-insulated. For example, CosyWall insulation is water repellent and made from glasswool making it extremely useful in our New Zealand climate.

3. Structural insulated panels (polystyrene and polyisocyanurate): Best installed during building, as the panels cannot be squeezed into tight spaces. Offers great insulation, but can work too well, encouraging damp. Panels emit toxic smoke when burned. Polyisocyanurate is a foil-type insulation, which works extremely well, but because it’s a foil barrier, it tends to encourage damp by not allowing any movement of air or moisture at all.

4. Polyurethane spray foam (open-cell and closed-cell): Sprayed into cavities (requiring minimal access) and expands to fit all available space. Great for cavity walls and tight spaces, and can be installed in new builds or already finished houses. Open-cell stops the movement of air and closed-cell stops the movement of both air and moisture.

Each material has different costs, benefits, disadvantages, and R-value. The R-value is the thermal resistance it offers or its efficiency at regulating the temperature.


Basically, everywhere. Here’s how it works: air travels from one extreme to another, until all temperatures are the same. Insulation creates a thermal barrier that helps to slow the movement of air in both directions. So if you want to keep your indoor temperature stable, you need to have a well-insulated home. Warm air can escape through all of your home’s barriers. It’s important to complete the thermal envelope by insulating your ceiling, floor and — most importantly and most forgotten — your walls.


As you can see, all insulation is not created equal. It has different costs, benefits, disadvantages, health and installation concerns, efficiencies and effectiveness. Installed well and properly, insulation can reduce heating costs, prevent the growth of mildew and mould, and keep your home a comfortable and stable temperature and ensuring a healthy home.

If installed incorrectly, it can affect your health, be less effective at thermal control and encourage the growth of damp issues. Insulation also ages, compressing and creating holes in the thermal envelope. It’s important to update your home’s insulation especially if your home is old.

Not sure when your home was last assessed for insulation? Give us a call or email us call on 0800 267 992 or to chat, obligation free, about your home. And if you’d like to find out more about heat loss, energy savings, renovation and insulation, check out our other articles.