External wall insulation (EWI)

STEICO External Wall Insulation (EWI) finished with a layer of render or cladding can help to improve the thermal and acoustic efficiency of a solid wall home. STEICO façade insulation is suitable for use in an external wall insulation system and can help mitigate some of the potential challenges of installing this type of insulation, including potential water penetration and moisture management issues.

What is external wall insulation and how does it work?

External wall insulation is a layer of insulation installed onto the façade of your building. Unlike internal or cavity wall insulation, external insulation is continuous without interruption from internal walls, wall ties, switches, plugs or other obstructions.

The benefits external wall insulation can provide when specified and installed correctly include:

Aesthetic improvements
Thermal efficiency improvements
Protects the building fabric
Acoustic damping

You can install a relatively thick layer of external insulation compared to other types of insulation system, subject to local planning conditions.

What are the potential challenges of external wall insulation?

While a suitable external insulation system can play a role in improving the energy efficiency of your home and limit the potential for cold and moisture related problems, the reverse can also be true if your system is inappropriate or poorly installed.

Gaps or cracks in your external wall insulation system can lead to water penetration and the following challenges:

Penetrating water leading to damp and leaks
Inadequate airflow which traps moisture, causing condensation build up.
Cold spots in the home and reduced energy efficiency.

Mitigating these will depend on the nuances of your building, but you can raise the likelihood of installing a system which performs as intended by considering the following factors:

Ensuring the external wall insulation is specified appropriately
Getting the thickness of insulation and your chosen finish right
Choosing materials which are appropriate for the job

How STEICO façade insulation can benefit your project

STEICO façade insulation systems are designed to help bring older solid wall buildings up to a more appropriate modern standard.

We offer two types of system, the first is single-layer external insulation system, comprised of

Existing solid brick wall
Render bonding coat
100-240mm of STEICOprotect L dry
Lime base coat, mesh and lime finish coat

The second is multi-layer external insulation system, comprised of:

Existing solid brick wall
STEICOjoist to desired thickness to act as a spacer.
Voids filled with cavity insulation STEICOzell / STEICOflex 036
40-60mm STEICOuniversal dry
Lime base coat, mesh and lime finish coat

Our wood fibre insulation products used as part of a complete façade insulation system can provide the following potential benefits for your project when specified and installed correctly:

Low thermal conductivity – STEICO façade insulation products can offer a lambda value as low as λD 0.037, making it a suitable choice for cold protection in most projects.
Carbon binding and responsible sourcing – As the products used in STEICO EWI systems have measured levels of CO2eq stored within them it is easy to calculate the total amount stored within every project and as they are sourced from PEFC certified forests (PEFC/04-31-2550), this can help to ensure that your external wall insulation system contributes towards your overall sustainability goals.
Algae and fungi protection – Diffusion-open wood fibre allows moisture to be absorbed, distributed and quickly dried through evaporation, and as the external surfaces are kept warm there is less potential for condensation or mould to form on the surface.