Cellulose Fibre Insulation in South Africa

There are many different insulation products on the market to choose from, cellulose fibre insulation is one of them. Also known as blow-in insulation or loose-fill insulation. We all need to be more energy-efficient and reduce power consumption. Choosing the right product that suits your needs is important.

The new building laws in South Africa have been set in 2011, stating that all newly built homes need to be insulated to reduce power consumption and help South Africa be more energy efficient.

What Is Cellulose Fibre Made From?

Cellulose is made from recycled newspapers. The newspapers get chopped up into fine, fluffy material. The newspaper does come with a few potential problems though. These problems vary from the newspaper being flammable to being a good nesting place for rodents. It can also be eaten by insects and can attract fungi and bacteria.

How Are These Problems Solved?

Cellulose has been treated with chemicals to solve these problems. Otherwise, you would have some issues with the product like the above mentioned. Over 20% of the cellulose product consists of chemicals and additives.

Chemicals In Cellulose Insulation

boric acid
borax
lime
ammonium sulfate
aluminium sulfate
ammonium phosphate
mono – and diammonium phosphate
aluminum hydrate
aluminum trihydrate
zinc chloride

If the improper amounts of these chemicals are used then it would not be able to control flammability and have no resistance to fire. On the downside, those chemicals could end up corroding metal or other materials the cellulose comes in contact with. The beams in your roof are normally held together with metal plates. If these metal plates were to corrode then it could lead to a roof deteriorating over time.

Cellulose Fibre Insulation Fire Rating

It’s important to note that cellulose insulation only achieves a BB 1/2 fire rating, meaning it is classified as combustible. Unlike non-combustible materials such as mineral wool or glass wool, cellulose fiber insulation is treated with fire-retardant chemicals to improve its fire resistance, but it still poses a fire risk. The BB 1/2 rating indicates that while it can slow down the spread of flames, it does not completely prevent combustion. Therefore, it’s crucial to consider these fire safety limitations when choosing cellulose fiber insulation for your building projects, especially in applications where stringent fire safety standards are required.

Cellulose Fibre R-values

Below we have listed all the cellulose fibre insulation R-values. It has a decent R-value. Very similar to that of Aerolite, Knauf, Fabufill or Isotherm insulation.

50mm – R-value – 1.25
75mm – R-value – 1.87
100mm – R-value – 2.50
115mm – R-value – 2.87
135mm – R-value – 3.37

Disadvantage Of Cellulose Insulation

It can settle over time which will reduce its efficiency and R-value. Additionally, expect up to a 25% settlement rate over the first few months of installation.
Its hygroscopic meaning it can soak up water and get heavy. Potentially causing a ceiling collapse. Any leaks from the roof or air conditioning system can cause some problems.
The insulation can mildew and can spread to the wood framing around it.
The wetness can cause electrical problems, and rust plumbing pipes.
Creates an enormous amount of dust when it is installed, so a certified breathing mask is absolutely essential.

Wet Cellulose Fibre

While having any type of ceiling insulation get wet can be a bad situation it is particularly bad for cellulose. This is because it is hygroscopic which means it can absorb water from its surroundings. When water hits the insulation it can compress it causing it to get heavy and potentially sag or collapse your ceiling boards.

Corrosive When Wet

However, what can make this situation more dangerous, is that fact that when wet the chemicals that make it fire-resistant becomes extremely corrosive. Results of these tests show that the wet cellulose can make the metal fasteners, electrical wires, and plumbing pipes rust when in contact with the wet insulation for long periods of time.

Testing And Removing Old Cellulose Fibre Insulation

If you have had cellulose fibre in your roof for a few years it would be a good idea to get a sample out your roof and test it to see if it is still capable of being fire retardant. It’s often found that after a year or two, it does tend to lose its ability to be fire retardant.

Check the metal holding your beams together while you up there to make sure the metal is not corroding. In the event that the product needs to be removed, follow the steps below:

Step 1

Firstly, make sure the vacuum is outside of the house if possible. Once the vacuum is outside run the hose into the roof through a window or a vent. You can even open up one or two tiles in your roof where the plastic underlay joins and fit the hose through the opening in the roof you have created. Don’t change the bags inside your house.

Step 2

Put a large bag into the vacuum. Even a plastic trash bag will do, just make sure it is sealed properly and won’t break. Have someone to help you on hand to keep an eye on the bag and the vacuum outside. When the bag gets full, have your helper remove the bag. Tie it closed and reload the vacuum with a new bag. Make sure the bag is sealed properly after removal.

Step 3

Make sure that you have the correct safety gear on. This should include a good respirator. You do not want to breathe in insulation chemicals of any kind. Start by vacuuming in the area closest to you and work your way around the roof. Be careful to not hit and damage any electrical wires or pipes. It is quite difficult to remove cellulose fibre insulation. So if you can, always hire a professional company to remove the old insulation for you. A professional company will come with the vacuum and bags ready for the removal process.