XPS Insulation

Extruded Polystyrene XPS is a modern insulating material with fantastic thermal properties, good moisture resistance and high strength. This extruded polystyrene (XPS) board is a high-density board that can be used for various applications on buildings, including DPC insulation, extending concrete windowsills or providing insulation backing where EPS is not suitable to use. The material has a smooth closed-cell surface ready for use.

These XPS boards can be used on timber, masonry and system build properties, as well as for tile hanging and as the base for a wide range of rendering systems.

XPS Features

• Closed-cell structure provides low thermal conductivity.
• Hydrophobic: The rate of absorption of water is practically zero when immersed or diffused.
• High mechanical strength
• Lightweight
• Chemical resistance to acids, bases, water and water-based paints, alcohol and alcohol-based paints, salt and seawater, cement and mortar.
• Does not cause corrosion.
• Contains flame retardant but must not be exposed to open flames or sources of ignition.

Preparation

Use a protection mat to prepare the property before applying the insulation to the DPC. We recommend the use of a hot knife or hot wire cutter to minimise mess.

Application

The XPS insulation boards should be installed in accordance with a project plan or a brief prepared by the architect. The boards  – if being applied to the area below the DPC or attached to the substrate – should be fixed using a quick-drying mortar or adhesive (see EWI-225 Premium Basecoat).

After having been fixed to the area below the DPC or on the sills (when left to dry), the work area should be covered sufficiently to prevent water penetration or exposure to UV light. When set and ready, apply the basecoat or mortar ready to sink into the Fibreglass Mesh. Once this has been installed, the substrate is ready for the application of the topcoat.