External Wall Insulation (EWI) is the application of an insulation layer to the outside wall of a building in order to improve the building’s energy efficiency.
By minimising heat loss in cold weather and heat gain in warm weather, EWI creates a much more comfortable living environment and reduces heating costs.
EWI is a composite system made up of three basic components: an insulate, a fixing, and a render or cladding. The insulate is secured to the wall using either special adhesives or purpose-made fixing screws/dowels. The final surface, which provides both the aesthetic and weatherproofing functions of the wall, is usually a coloured render but could also be a brick effect or other specialist finish.
A range of EWI systems are available allowing the building owner to prioritise between cost and technical performance.
SILICONE & ACRYLIC FINISH
A base coat render is applied at a minimum thickness of 8mm. This is ruled to provide a flat surface. A primer coat is then applied followed by an acrylic finish at 1-2mm.
SCRATCH RENDER
This product is applied over a base coat render at approximately 10mm thickness. The surface is then scratched back using a nail float resulting in a textured finish.
BRICK EFFECT RENDER
Two or three coat brick effect render, used to simulate the appearance of brickwork. A coloured mortar coat is trowel applied and the top coat is applied in a contrasting colour whilst still soft. This is then carefully set out and cut back using a specialist cutting tool.
DRY DASH FINISH
A coloured render coated with a spar dash finish. A wide range of aggregates in various colours can be used to dash the surface, which is applied at 8mm whilst the render is still soft.
BRICK SLIPS
Giving the traditional feel of a building, Brick Slips are produced by removing the face of existing bricks thus achieving genuine brick effect finish.
