Why is EWI used for moisture management?

Weber UK

This blog is written in partnership with Pyramid Solutions, an External Wall Insulation company based in Essex. 

Visit their website here


External Wall Insulation, or EWI, is a system that involves the application of insulation material to the exterior surface of a building, creating a thermal envelope. The insulation layer is then covered with a protective render and decorative finish. EWI serves a dual purpose, significantly improving a building's energy efficiency and providing a shield against moisture-related issues.

So, why is EWI used for moisture management?

Condensation Control:

EWI plays a key role in controlling condensation within a building. By insulating the exterior walls, the system keeps the internal surfaces warmer, reducing the likelihood of moisture-laden air reaching its dew point and forming condensation. This helps prevent the growth of mould and mildew, safeguarding indoor air quality and occupant health.


Unlike some traditional insulation methods, EWI systems are designed to be breathable. This means they allow water vapour to pass through, preventing the build up of trapped moisture within the walls. The breathability of EWI is crucial in maintaining a balanced and healthy indoor environment while protecting the structural integrity of the building.

Thermal Bridging Reduction:

By wrapping the entire building in a continuous layer of insulation, EWI reduces thermal bridging – areas where heat can escape, or cold spots can form. This not only enhances energy efficiency but also minimises the risk of localised temperature differences that could lead to condensation and moisture-related problems.

Increased Durability:

EWI contributes to the overall durability of a building by protecting the underlying structure from the detrimental effects of moisture. By managing moisture effectively, EWI helps prevent the corrosion of structural elements and deterioration of building materials, ensuring a longer lifespan for the entire structure.


External Wall Insulation has emerged as a versatile solution that extends the life of existing buildings by providing thermal insulation to keep the old structure warm and stable. Its ability to manage moisture effectively contributes to improved energy efficiency and enhanced durability. As the construction industry continues to prioritise sustainable practices, EWI stands out as a key player in creating buildings that not only withstand the test of time but also prioritize the well-being of occupants and the environment.

If you have any questions, please do not hesitate to get in contact with your local Weber contact to request a full specification for your EWI project, or to answer any questions you may have.

Click Compare to help you choose the right product for your project, if you need further assistance please email technical@netweber.co.uk