Such features require specialist design considerations in terms of insulation to ensure a building’s overall thermal performance meets regulatory requirements. Chris Knowles, Business Manager (Vacuum Insulation Panels) at Recticel Insulation, one of the world’s leading PIR manufacturers, looks at the challenges involved with roof terrace insulation and highlights the benefits of a product that is designed to overcome such issues.
With suitable plots at a premium, an increasing number of property developments are being built with outdoor space to optimise available land. As such, keeping thresholds low through the innovation of ultra-thin insulation and waterproofing design is a growing challenge. The following guide provides some useful tips on dealing with roof terrace design issues, which you can overcome with VIPs (vacuum insulation panels). This super-slim solution offers maximum performance but at a much-reduced product thickness, thus overcoming threshold issues.
1. Prevention is better than cure, a saying that is particularly pertinent to house-building and renovation. In the case of roof terrace insulation, it means providing answers for some initial vital questions, such as how can specified U-values be achieved whilst working within insulation height restrictions? This is where standard PIR products fall short in terms of terrace installation performance. It generally means either compromising on U-value outcomes or compromising on drainage by installing channels or raising the low thresholds. VIP solutions are ideal for terraces and flat roofs as they deliver high thermal performance without the need for structural alterations. Working with a specialist roofing design team such as Recticel’s tapered roof insulation division, Gradient, will ensure the specified VIPs meet a project’s design, optimising performance, materials and cost.
2. Conduct a site survey. In many instances, the initial take-off drawing/specification of a project will differ from the ‘reality’ on site. Therefore, it is always recommended to have a site survey carried out before ordering a VIP solution. Given that VIPs cannot be cut or altered on site, dimensions must be correct before order. This should also consider potential obstructions or openings, such as rooflight and drainage outlets, which would affect the layout of a vacuum insulation panel scheme.
3. Use a protected VIP, as vacuum insulation panels are vulnerable to puncture. If this happens, the VIP’s insulation value will degrade to that of a conventional PIR material. A construction site could, therefore, pose problems for VIPs during their handling and installation. The best solution is to utilise a product such as Recticel’s Deck-VQ, as the VIP is fully encapsulated within a high-density PIR protective shell. This provides reassurance that the product can be easily installed by the contractor, with the knowledge that the VIP’s excellent thermal insulation value will be maintained.
4. Ensure the contractor is aware of the insulation technology used in a roof terrace scheme, particularly concerning VIPs. They need to be mindful that VIPs cannot be cut or modified on site, which is a complete shift of mindset from conventional insulation products.
5. Always use the design layout provided. By working with Gradient, a full project design package is supplied. This will create a scheme layout in conjunction with the product delivery and ensure the quantity of material delivered is optimised to eliminate or reduce site waste. Therefore, the design scheme must be followed exactly to avoid installation difficulties and product shortfall.
Roof terracing can add much-needed living space to a building, as well as increase its monetary value. Although perhaps peripheral in terms of a property’s overall design, its thermal performance is as crucial as the other elements which make up a building’s fabric.