IsoBoard is a rigid, high density, extruded polystyrene, manufactured in different thicknesses and lengths for applications such as roofing, walls, floors and retrofit.


IsoBoard insulation provides a barrier to heat transfer, which keeps heat energy on one side of the board and controls where heat energy should be, either inside or outside.


Installing an insulation such as IsoBoard eliminates the discomfort of hot or cold weather in your home and business creating a long-lasting hot/cold barrier.


Technical Data

  • Ceiling insulation
  • Cavity Wall insulation
  • Inverted roof insulation
  • Over rafter and truss insulation
  • Surface bed insulation
  • Foundation perimeter insulation
Fire Safety:IsoBoard has no flame spread characteristics. IsoBoard is suitable for all occupancy types in horizontal and vertical applications, except for buildings where non-combustible materials are prescribed by SANS 10400.
Water Absorption:Sample board immersed in water to 50 mm depth for 24 hours.
Heater Transfer:IsoBoard insulation provides a barrier to heat transfer, which keeps heat energy on one side of the board or the other.
Durability:IsoBoard has been tested and proven to outlast most insulation products due to its ability to last much longer intougher conditions. IsoBoard extruded polystyrene keepsa high R-Value throughout its lifespan.
Thermal Properties:Significantly reduces heat gains & losses.

IsoBoard has been tested and proven to outlast most insulation products due to its ability to last much longer in tougher conditions. IsoBoard extruded polystyrene keeps a high R-Value throughout its lifespan.

IsoBoard is already a perfect white which keeps your installation simple as painting and priming is not necessary. Wood effects can be created using painting techniques and the already shaped panels create lasting style.

The thermal conductivity (k-value) of 5 year aged Isoboard at 90% relative humidity is 0.03 W/m°C. This K-Value for both aged and wet IsoBoard is termed the “design value”, used when performing heat flow calculations for building elements employing Isoboard Insulation. The “design value”is the worst case expected conductivity of IsoBoard at the end of the building useful life. You can rely on calculated by dividing the thickness of the IsoBoard by the design K-Value, to achieve the following table:

Isoboard Thickness(mm)Design R-Value(m °C/W)

IsoBoard is classified as B/B1/2/H&V in terms of SANS 428 Classification table. This means that although the board is combustible, it poses no flame spread hazard and can be used in any building type in a horizontal or vertical application, both with and without sprinklers, with the exception of regulated buildings requiring non-combustible materials, such as hotels and hospitals. Exposed to fire, Isoboard shrinks away from the heat source. There are no flaming droplets, and no flame spread. The gases released as a product of combustion are less toxic than burning wood.

Fit brandering to room perimeter, and at max 700mm centres one direction only. IsoBoard is fixed to brandering using adhesive and concealed fixing clips. Use dry wall screws at 300mm intervals on the perimeter where cornices will be installed. Applying adhesive in 5ml blobs every 200mm, coverage is approximately 30m² per Ltr. Clip usage is 3 per m².


IsoBoard can be retrofitted below an existing ceiling to cover damage, provide insulation or change the appearance. Isoboard can also be fixed below a concrete soffit. Fit brandering below the soffit or other ceiling if necessary to allow for rough or sagging surfaces. When fixing IsoBoard between existing trusses, rafters and brandering, use screws, clips and adhesives as for nail-up ceilings.

The boards are laid horizontally in long lengths, always beginning and ending on a truss or rafter. Fix a counter batten above each truss or rafter, secured with screws through the IsoBoard into the beam below at 300mm intervals. Battens or purlins are fixed to the counter battens. If fitting IsoBoard below a steel roof, install fibrous acoustic insulation over IsoBoard to dampen weather noise.

Cavity wall insulation is an excellent way of controlling heat transfer through walls, as well as preventing moisture condensing on and penetrating the inner leaf. As homes become smaller and taller, the ratio of roof area to wall area decreases, and the impact of heat transfer through the walls increase. Essentially, the boards are fixed horizontally to the inner leaf using wire ties, alternative ties are used to secure the two leaves together across the cavity. Remember to keep the cavity clean.

IsoBoard is laid above the water proofing layer and secured in place using ballast to prevent wind uplift. The ballast layer can be gravel, paving stones or a concrete screed. The water proofing is protected from the sun and weather by the IsoBoard, rendering it practically maintenance free. The thermal mass of the concrete slab is maintained at the internal temperature of the building, protected from daily variation, helping to maintain a constant temperature within the building. Inverted roof insulation can be installed onto a new building, or as a retrofit solution later. Isoboard excels in inverted and green roof applications, as it is the insulator least affected by water.


As a “One-stop Insulation shop” Insulpro CC can offer insulation solutions across all temperature ranges and applications.


Tel: 011 835 2128 / 29 / 30
Address: 52 5th Street, Booysens Reserve, Johannesburg, 2091


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