46 RCI 0714

RCI JULY 2014

INSULATION 046 JULY 2014 RCIMAG.COM Don’t dig down By Tony Milichap, Kingspan Insulation technical manager The data from the latest English Housing Survey shows that dwellings constructed prior to 1965, when the first requirements for domestic insulation were included in the Building Regulations, continue to make up 57% of the UK’s housing stock. These properties are often poorly insulated, and improving their thermal performance is essential both to help reduce carbon emissions, and to guard against rising energy bills. Whilst the most common insulation retrofits are on external walls and attic spaces, floors can also account for a significant proportion of heatloss from properties. All too frequently however, a lack of construction depth or space, and limited access for heavy machinery, means that areas such as solid floors are left partially or wholly uninsulated. The need to keep floor build-ups as thin as possible in order to avoid either digging down or losing headroom is therefore a key objective on many refurbishment projects, and that requires a very high performance insulation. Next generation insulation Vacuum Insulation Panels (VIPs) offer a cuttingedge solution, matching the performance of the next best alternative, at a fraction of the thickness. Unlike conventional insulation, VIPs feature a micro-porous core, which is evacuated and sealed in a thin, gas-tight membrane. The membrane has to be capable of withstanding atmospheric pressure, and of maintaining the vacuum over time. This allows the panels to achieve aged thermal conductivities as low as 0.007 W/m·K, up to five times better than many commonly used insulation materials. This superior thermal performance has led to VIPs becoming increasingly popular on the Continent, particularly in Scandinavia, Germany and Switzerland. In these regions, the panels are typically used in applications where design or refurbishment constraints make the use of traditional insulation impractical. The panels are supplied with rigid thermoset insulation infills of the same thickness. These can be cut to fit around penetrations or used to fill small gaps in the insulation layer. Floor it Solid floor applications provide an excellent example of how VIPs can provide a viable solution to a common retrofit problem. In order to accommodate an effective thickness of traditional insulation, it is often necessary to manually dig out and remove a large volume of material, leading to increases in project times and cost. For example, the minimum U-Value target for refurbished floors under Approved Document L1B 2013 is 0.25 W/m².K. To achieve this in a typical Victorian terrace with a 36m² (perimeter / area ratio of 0.3) floor area, where the existing floor is being replaced, 60mm EPS (0.038 W/m.K) is needed. This requires 2.16m³ of ground material to be excavated by hand and removed from the site, greatly extending the construction program. In contrast, a VIPs system including 15% infill panels can achieve the required U-Value performance with a thickness of just 26mm, meaning less than one cubic metre of soil needs to be removed. This should allow work to be completed more quickly and easily, helping to minimise disruption for the building owners and reducing construction costs. A further thickness of rigid thermoset infills should also be installed vertically around the floor edge to help limit thermal bridging. The alternative for refurbishment projects is to raise the existing floor level. However, this will reduce the floor to ceiling height within the room and requires fixtures and services such as plug sockets, door lintels and radiators to be raised in line with the floor level, creating yet more remedial work and again increasing the time and cost involved. VIPs provide an ultra-thin solution, helping to keep projects on track without compromising on head height. Getting the best results By preparing a layout for the VIPs system prior to installation, the desired U-value can be achieved with the absolute minimum insulation thickness. Installing VIP systems with LABC Registered Details can also help to streamline the Building Control checking and approval stage, generating further savings. Futureproof solution With energy price rises expected to continue over the long-term, along with the introduction of tougher regulations, the benefits of insulating “problem areas” such as solid floors are only likely to increase. VIPs offer a simple and slim line solution to achieving outstanding thermal performance without the drawbacks associated with thicker, traditional insulation. www.kingspaninsulation.co.uk Kingspan Insulation’s specialist technical support team provides clear layouts for each application, ensuring the desired thermal performance is achieved with a minimal build-up


RCI JULY 2014
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