140mm Expanded polystyrene (EPS) insulation board is a high-performing thermal insulation core for our external wall insulation systems. It significantly enhances the thermal efficiency of buildings, improving U-values and reducing the risk of water penetration and condensation. 140mm EPS boards are compatible with timber, masonry, system-built properties, tile hanging, and a wide range of rendering systems. They are specifically designed to be applied to masonry or timber-backed walls using adhesive and mechanical fixings, and can also be installed in cavity voids for cavity wall insulation.
140mm Stylite Plustherm Grey EPS 70 Insulation Board is the most popular material for external wall insulation systems due to its excellent value for money. Choosing a cost-effective 140mm EPS insulation board allows for cost savings without compromising on quality or thermal performance.
When installing 140mm EPS as part of an EWI system, applicators will find that the installation materials are more affordable. EPS is extremely lightweight, requiring a lower strength adhesive and plastic rather than metal fixings. Additionally, 140mm Stylite EPS is non-breathable, allowing for the use of lower-cost thin coat renders, such as EWI-075 Silicone Render or EWI-040 Acrylic Render.
140mm Stylite Expanded Polystyrene insulation boards are an ideal solution for insulating external walls. They can be easily fixed to the existing wall substrate, instantly improving both the appearance and thermal performance of the wall. Insulating the external side of the wall, rather than the internal side, reduces the risk of interstitial condensation forming within the wall.
Stylite 140mm External Wall Insulation board is compatible with various wall constructions, including solid brickwork and timber frame walls. Typically, external wall insulation is covered with a rendered finish to protect the insulation. The application method for this finish varies depending on the system used. Additionally, 140mm Stylite EWI boards are suitable for use in rail or drained cavity EWI systems.
Use netting on scaffolding to minimize the amount of polystyrene blowing in the wind. We highly recommend using a hot knife or hot wire cutters to reduce the number of polystyrene offcuts, though a standard knife can be used if necessary. Ideally, cut the 140mm EPS insulation boards in a covered area to prevent offcuts from blowing around.
Always install EPS insulation boards according to the manufacturer’s installation guidelines, covering all aspects of design and application. Initially, you can fix the EPS boards to the substrate (masonry or timber) using mortar/adhesive or mechanical fixings.
Once the boards are fixed to an external wall, we recommend covering them with an outer layer, such as a mortar basecoat or netting, to protect from excessive heat, moisture, and UV exposure.
Before applying the basecoat or mortar for the fibreglass mesh, rasp or sand down the top surface of the boards to create an abrasive surface. Once this is done, the substrate is ready for the application of the fibreglass mesh. For more detailed instructions, please download the full installation guide.
Check the manufacturer’s date of expiry for shelf life. Store in a dry place, in the original packaging. Avoid exposure to excessive heat or UV light.









