The insulation rendering process is used to transform old, solid external walls and improve their thermal efficiency. This is especially important for existing buildings where internal lining may be difficult or where it would alter critical internal dimensions.

The method typically involves external wall insulation render insulative boards that are designed to enhance the thermal performance of your home, these can be made from a variety of materials including polystyrene and rock wool – a specialist through-coloured render then covers them which acts as both weather protection and decorative finish. This render is often called a thermal rendering system or EWI and can help to reduce heat loss by 75% (a standard solid wall can achieve a U value of around 2.1 when rendered) and can help to improve air tightness which significantly lowers heating bills.

Enhancing Building Performance: The Benefits of Exterior Insulation Cladding Systems

A good quality insulated render should be permeable to allow moisture to pass through it, this allows humidity to move away from the home rather than trapping it which can lead to rot and mould. Responsible renderers will also create thorough plans to implement new ventilation systems where required to ensure your home remains a healthy place to live.

Traditional insulated renders require the use of an adhesive which is applied directly to the cladding, this is problematic for a number of reasons – Firstly, it is not breathable which means that air movement behind the insulation will cause it to deflate and can be unsightly to look at – secondly the adhesive is prone to leaking which again can lead to damage and moisture leakage.