Insulation designed to weather a storm

By Knauf Insulation UK & Ireland
March 08, 2021

This time last year, the UK was battered by four storms in quick succession, the latest in a growing list of extreme weather events to hit the UK. Experts predict that as the climate crisis worsens, summers will get hotter and dryer, while winters will be warmer, wetter and punctuated by severe storms.

Working in the construction industry, it’s easy to look on warmer weather as a boon. After all, who doesn’t want to make hay while the sun shines? But it comes at a cost, and one that is not just wreaking havoc on existing properties but building sites too.

Rising temperatures mean the atmosphere has to absorb more water vapor, resulting in sudden downpours that can cause flash floods. While pressure fronts result in strong winds, which tend to do the most damage when they gust, placing sudden, immense pressure or loads on a structure.

So, what should be done if these events, far from being ‘extreme’ or once in a decade, become the norm?

Buildings need to be resilient. Typically, when we talk about resilient buildings, we are referring to how their fabric delivers high thermal, fire safety and acoustic performance in the real world and over the long term. But, to create a resilient building, the materials used must be able to withstand even the most extreme conditions during construction without damage or loss of performance.

For example, Knauf Insulation RainScreen Slab has been specifically designed for use on high rise residential applications. We recognise that the insulation may be exposed to the elements during construction, that’s why it has been wind load tested by the Building Research Establishment to a maximum design pressure of 3,600Pa or 76m/s (170mph) – equivalent to a category 5 hurricane. By contrast, Storm Ciara, a tropical cyclone considered the most significant storm to affect England and Wales since 2014, triggered 25 weather stations with gusts of over 31m/s (69mph) and hit top speeds of 43m/s (97mph) inland.1

Like all our insulation for external applications, RainScreen Slab is manufactured with a water repellent additive to preserve its integrity during construction and throughout its lifespan.

As a result, tests by the European Insulation Manufacturers Association (Eurima) found that when correctly installed, Mineral Wool insulation retained its thermal performance even after 55 years’ service. This means that even if Mineral Wool insulation is subject to the harshest downpours during installation, it will recover its thermal performance when it dries out. It is, however, also important to ensure it is stored correctly on site to maintain its performance.

As well as being able to cope with the most extreme weather, RainScreen Slab has a thermal conductivity of 0.034W/mK and is non-combustible with the best possible Euroclass A1 Reaction to Fire Classification. It has BBA certificates for use in rainscreen cladding systems, and behind masonry. It complies with building regulations and will not contribute to the development or spread of fire, should it occur. RainScreen Slab is also manufactured with our unique bio-based binder ECOSE® Technology, which contains no added formaldehyde or phenol.

High winds and rain don’t just lead to delays on site, they can also damage the materials being used. It therefore makes good business sense to specify insulation that has been specifically designed to withstand the very worst the British weather can throw at it!