Is External Style of Wall Insulation Fireproof? 

External wall insulation (EWI) systems have become increasingly popular in recent years as homeowners and building owners seek ways to improve energy efficiency and reduce their carbon footprint.

However, in the wake of the Grenfell Tower tragedy, concerns about fire safety have taken center stage. This article explains whether external wall insulation systems are fireproof and what factors affect fire resistance.

Understanding the Fire Resistance of EWI Systems

In the context of EWI systems, fire resistance refers to the ability of the insulation material, render, and overall system to resist the spread of fire and maintain structural integrity.

The fire resistance of EWI systems is influenced by these factors:

  1. Insulation material
  2. System design
  3. Installation quality

Is External Insulation A Fire Risk?

All insulation materials carry some level of fire risk, but the degree of risk varies. Mineral wool and expanded polystyrene are the two main materials that are recognized when it comes to fire resistance. Let’s talk about them in detail.

Mineral Wool Insulation

Mineral wool insulation is made from natural rock or slag and is widely recognized for its excellent fire-resistant properties when exposed to fire. It does not readily ignite or contribute to the spread of flames. 

Many mineral wool EWI systems have achieved fire resistance ratings of up to two hours or more, depending on the specific system design and installation. This characteristic makes mineral wool a preferred choice for EWI systems where fire safety is a priority.

Expanded Polystyrene (EPS) 

Expanded polystyrene (EPS) is another common insulation material used in EWI systems. EPS is a combustible material that can contribute to the spread of fire if not properly protected or installed. In certain situations, the use of EPS insulation may be restricted or subject to additional fire-resistant measures such as high-rise buildings or buildings with specific fire safety requirements


So, is external wall insulation fireproof? All high-quality EWI systems are fire resistant. But the true strength of a fire-resistant EWI system lies in its overall design which should incorporate appropriate fire-resistant components, barriers, and measures tailored to the specific building and its requirements. 

This underscores the importance of working with qualified professionals who can ensure that the EWI system meets or exceeds the necessary fire resistance ratings and complies with all applicable regulations.

If you need help with your external wall insulation, don’t hesitate to reach out to us. We have the right knowledge, resources, and commitment to help you create buildings that are not only energy-efficient but also resilient in the face of fire hazards.

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