Expanded polystyrene EPS insulation board is high-performing thermal insulation at the centre of our external wall insulation systems. It upgrades the thermal properties of a building, improving U-values, reducing the risk of water penetration and condensation. EPS boards can be used on timber, masonry and system-built properties as well as for tile hanging and a wide range of rendering systems. It is designed to be applied externally to masonry or timber-backed walls using adhesive and mechanical fixings. EPS boards can also be installed in the cavity void if the property is being insulated using cavity wall insulation.
The most popular material used in external wall insulation systems, one of the stand-out benefits of using EPS insulation for your project is that it’s great value. Choosing a cost-effective insulation board such as EPS means that you can cut down on cost without sacrificing quality or thermal performance. When installing EPS as part of an external wall insulation system, applicators will also find that the associated materials required for the installation of this particular material are available at a much lower cost. This is because EPS is such a lightweight material, the required adhesive is of a much lower strength and the fixings are plastic rather than metal. EPS is also a non-breathable material and so lower-cost thin coat renders can be used in combination, for example, the EWI-040 Acrylic Render.
- Composition: expanded polystyrene, graphite
- Thermal Conductivity: 0.032W/(m2K)
- Reaction to Fire: Class E
- Compressive strength: 70kPa
- R-value: 1.97W/(m2K)
- Weight: 13.02kg
- Weight/m2: 1.13kg
- Size of boards: 1200 x 600mm
- Thicknesses available: 20mm, 30mm, 50mm, 70mm, 90mm, 100mm, 150mm and 200mm
- Coverage in pack: 0.72m2
- Bending strength: >= 75kPa
Use netting on scaffolding to reduce the amount of polystyrene blowing about in the wind. Try to use a hot knife or hot wire cutters to minimise the number of polystyrene offcuts, although a standard saw can be used – ideally, cut the EPS insulation boards within a covered area to reduce offcuts blowing around.
EPS insulation boards should be installed in accordance with the manufacturer’s installation guidelines – these should cover design and all aspects of the application of the insulation. The boards are initially fixed to the substrate (masonry or timber) either by a mortar/adhesive or simply by mechanical fixings.
After having been fixed to an external wall, the EPS insulation boards should be covered with an outer layer, either by the mortar basecoat or simply by a netting covering to protect from excessive heat, moisture and UV exposure.
Before applying the basecoat or mortar for the fibreglass mesh, the top surface of the EPS insulation board needs to be rasped or sanded down to produce an abrasive surface. Once this has been done, the substrate is ready for the application of the fibreglass mesh. For further information, please download the full installation guide.
Shelf life: please see the manufacturer’s date of expiry. Keep in a dry place, in the original packaging. Avoid excess heat or UV light exposure.