isoboard insulation
isoboard ceilings



IsoBoard insulation is a popular ceiling in South Africa for improving energy efficiency and reducing heating and cooling costs. It is a rigid, lightweight board made from extruded polystyrene foam that is easy to install and provides excellent thermal resistance properties.

IsoBoard ceilings can be installed between roof rafters, under tiles or sheeting, or on the ceiling surface itself. It helps to prevent heat from escaping during winter and entering during summer, providing a more comfortable indoor environment year-round.


Other Insulation Products Include:


  1. KNAUF


Most of the external heat that flows into a building comes in through the roof. So it makes sense to reduce the flow of heat through the roof structure as much as possible. ISOBOARD ceilings can be used to enhance energy efficiency as well as enhance the visual look of the ceiling.




ISOBOARD is the name of the insulation product. It’s a high-quality, rigid, extruded Polystyrene foam manufactured in South Africa. Providing much higher R-values than a standard rhino board ceiling. It is manufactured with microscopic gas-filled cells which resemble a honeycomb. This also gives it strength, making it rigid.




R-value is a measure of thermal resistance, indicating how well an insulation material resists the transfer of heat. The higher the R-value, the more effective the insulation is at reducing heat flow. IsoBoard ceiling insulation has different R-values depending on the thickness of the board used. Here are some examples of typical R-values for IsoBoard ceiling insulation:



The appropriate R-value for an IsoBoard ceiling will depend on the climate zone in which the building is located, the desired level of thermal resistance, and the roof construction. It is important to consult with a professional installer to determine the appropriate R-value of IsoBoard insulation to achieve optimal performance and energy savings for your specific application.




IsoBoard insulation is resistant to water and moisture, which makes it a suitable insulation material for areas that may be exposed to moisture or humidity, such as roofs and basements. The closed-cell structure of the extruded polystyrene foam prevents water from penetrating the material and helps to prevent the growth of mold and mildew.

It also maintains its insulating properties when exposed to moisture, unlike some other insulation materials that can lose their effectiveness. However, it is important to note that the water resistance may be compromised if the material is punctured or damaged during installation or handling. Proper installation and maintenance of IsoBoard insulation can help to ensure that it remains water-resistant and provides energy savings.




ISOBOARD ceilings have many benefits over traditional ceilings. A traditional ceiling does not offer much of an R-value or insulation. Although it costs more than a traditional ceiling, it’s worth the price.


  1. Extruded Polystyrene foam offers low thermal conductivity
  2. High resistance to water vapour diffusion
  3. High resistance to water absorption
  4. The density distribution is consistent
  5. Aging resistance
  6. Resistance to bacteria
  7. Resistance to microorganism growth
  8. It’s a strong and sturdy product




The cost of IsoBoard insulation in South Africa varies depending on the thickness and size of the board. On average, the installation price of IsoBoard ranges from R300 to R650 per square meter. Thicker boards and larger sizes tend to cost more. Other factors that may affect the cost include the supplier and the location of the project.

It’s essential to consider the long-term benefits of using it, such as energy savings and improved thermal performance when comparing prices with other insulation materials. The cost of installation should also be taken into account when budgeting for this product.




The fire rating of IsoBoard insulation in South Africa depends on the thickness and density of the board. Generally, IsoBoard insulation has a Class B/B1 fire rating, which means that it has a low flammability and low smoke emission rate. However, thicker and denser IsoBoard insulation may have a higher fire rating, such as Class A or Class 1.

It is important to note that the fire rating of IsoBoard insulation may vary depending on the installation method, surrounding materials, and other factors. To ensure compliance with local building codes and fire safety regulations, it is recommended to consult with a professional installer and check the specific fire rating of the IsoBoard insulation being used for your project.




Extruded polystyrene (XPS) and expanded polystyrene (EPS) are two common types of foam insulation materials used in the construction industry.

XPS is made by melting polystyrene pellets and extruding them into rigid foam boards. It has a closed-cell structure, which makes it highly resistant to moisture, and it has a higher compressive strength than EPS. XPS insulation is more expensive than EPS, but it provides better thermal resistance and is more durable.

EPS, on the other hand, is made by expanding polystyrene beads with steam and then molding them into shape. It has a lower density than XPS and is less expensive. EPS has an open-cell structure, which makes it more permeable to moisture than XPS. However, EPS is a good insulator and can provide excellent thermal resistance when used in sufficient thicknesses.

When deciding between XPS and EPS insulation, it is important to consider the specific insulation requirements of the project, as well as factors such as cost, durability, and moisture resistance. Both XPS and EPS insulation can be effective insulation solutions when installed correctly and in accordance with manufacturer guidelines.




IsoBoard ceiling insulation is a durable and long-lasting insulation material that can last up to 50 years or more, depending on the quality of the material, the thickness of the board used, and proper installation and maintenance. It is made from extruded polystyrene foam, which is a closed-cell material that does not break down or lose its insulating properties over time.

In addition, IsoBoard insulation is resistant to moisture and does not support mold growth, which can prolong its lifespan. Proper installation, including careful handling and sealing of joints and edges, is essential for ensuring optimal performance and longevity. It is also important to maintain the insulation by keeping it free of debris and checking it periodically for signs of damage or wear.




Proper installation of IsoBoard insulation is crucial for performance. Here are some guidelines for IsoBoard installation:


  1. Measure the area to be insulated and calculate the amount of board needed.
  2. Ensure that the surface to be insulated is clean, dry, and free of debris.
  3. Cut the board to size using a fine-toothed saw or insulation knife. Wear protective gear, such as gloves and a mask, when cutting and handling the insulation.
  4. Apply adhesive to the surface of the area to be insulated using a notched trowel or spray adhesive.
  5. Press the board into place, ensuring that it is firmly attached and free of gaps or air pockets.
  6. Seal the joints and edges of the insulation with tape or sealant to prevent air leakage.
  7. Install a vapor barrier if required by local building codes or climate conditions.
  8. Follow manufacturer guidelines for any additional installation requirements or considerations, such as fire safety or acoustic insulation.


It is important to consult with a professional installer or follow manufacturer guidelines for specific installation instructions and recommendations. Improper installation can compromise performance and effectiveness and may result in energy loss or other issues.


Read more: Supreme Ceilings


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