INSULATION T
he UK housing stock comprises over 8 million homes featuring solid walls - a construction method that poses significant challenges when it comes to energy efficiency and thermal comfort. Solid wall construction is common in homes built before the 1920s. However, it presents a significant challenge when it comes to heat retention and moisture management. Without effective insulation, solid wall homes are prone to heat loss, drafts, and the risk of interstitial condensation – moisture inside the wall that leads to serious problems like damp, mould, and structural damage.
Historically, merchants and builders have used various insulation approaches for solid wall properties, with varying degrees of success. Internal wall insulation (IWI), for instance, can be disruptive and often reduces valuable living space. In the past, external wall insulation (EWI) has been hindered by the use of non-breathable materials that can trap moisture within the building fabric. These conventional insulation solutions, have not always addressed the fundamental need for moisture-management, an approach that preserves the structural integrity of solid wall homes. This is why we always guide merchants and builders to breathable EWI systems because they tackle the root causes of energy inefficiency and indoor air quality issues.
The challenge of solid walls Matthew Woodhams, Technical Specification Manager at Baumit says that Breathable EWI systems are designed specifically to address the challenges posed by solid wall construction .”At the heart of this approach is the recognition that effective insulation is not just about reducing heat loss, but also about managing the passage of moisture through the building fabric.”
The key to success with EWI, he adds, is the use of highly permeable insulation materials. “Such as expanded polystyrene (EPS) boards featuring, for example, our OpenAir technology. These boards are perforated with tiny holes, allowing water vapour from inside the home to diffuse outwards without compromising the system’s thermal performance.
“This breathability is further enhanced by the use of vapour-permeable adhesives, basecoats, and topcoats, creating a seamless, moisture-managing envelope that prevents the buildup of interstitial condensation within the wall structure,” he says.
Optimal Indoor Climate Control Woodhams explains that, by allowing water vapour to escape the building, breathable EWI systems help to maintain a healthy, comfortable indoor climate. This is particularly important in solid wall homes, where the lack of a cavity can exacerbate issues related to high humidity, mould, and poor air quality.
UNLOCK SOLID SALES POTENTIAL
Breathable External Wall Insulation (EWI) creates important sales opportunities for builders’ merchants. BMJ finds out why.
“With a breathable system, merchants can offer their customers a solution that provides a more energy efficient, well-regulated environment, with humidity levels kept within the recommended 40-60% range.”
Thermal Efficiency
As well as being breathable, Woodhams says that OpenAir EPS or natural EWI insulation such as wood fibre board delivers exceptional thermal performance, meeting and exceeding the latest energy efficiency standards. By offering insulation materials with low thermal conductivity (lambda values), the system is able to achieve high R-values while minimising the thickness of the insulation layer. “Merchants that are asked about the longevity of EWI can reassure customers that they are designed to withstand the test of
September 2024
www.buildersmerchantsjournal.net
time, with a robust, weatherproof finish that protects the building from the elements. The use of high-quality primers, adhesives, and topcoats ensures a smooth, attractive facade that can be customised to suit the architectural style of the property,” he says. “During the regular training sessions we hold at the Baumit Academy in Maidenhead and Doncaster, a common question from merchant customers is about the final layer of the breathable EWI system. For this we recommend a weatherproof topcoat render that offers protection against the elements. It features a silicon binder and a filler to create a smooth, attractive finish that is quick-drying, even in damp conditions.”
When guiding customers on their choice of EWI it is crucial to consider the specific needs and characteristics of the building, Woodhams adds. “Factors such as the existing wall construction, exposure to weather, and any planning or conservation restrictions will all play a role in determining the most suitable solution.”
As the UK continues to address the challenge of improving the energy efficiency and indoor air quality of its solid wall housing stock, forward-thinking merchants can get ahead of competition by offering breathable EWI systems. This approach prioritises moisture management, thermal performance, and long-term durability, offering builders a comprehensive answer to the needs of solid wall homes. BMJ
19
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72
