Putting your trust in sustainable roofing

Reducing carbon emissions is an increasingly important issue for all organisations, and improving existing and new buildings’ sustainability is now seen as an integral part of delivering a high quality health service. It is estimated that the total carbon footprint of the NHS is 18 million tonnes CO2 per year, with around 22% of this quota resulting from energy usage and emissions from buildings. Sustainability factors are therefore becoming an increasingly important consideration when it comes to selecting materials for roof coverings in the health sector. Quite simply, the roof is no longer there just to keep the rain out, and the building warm. Modern technologies mean roofs are increasingly able to play a role in reducing carbon dioxide emissions in the atmosphere, and there are several ways of achieving this, including ‘green’ and ‘brown’ (or ‘living’) roofs, as well as solar photovoltaics (PV).
Green roofing

A ‘green roof’ consists of a living, vegetative system made up of a growing medium and vegetation layer at its outermost surface. The design and construction between the roof deck and the growing media varies, but there are usually a geo-textile filter, drainage layer, root barrier, and a waterproof membrane. The growing media depth can vary from 20 mm for sedum-type plants, up to one metre if large shrubs are chosen as part of the vegetative system. An advantage of placing the insulation above the waterproof layer, which is possible on a green roof, is that it protects it from temperature extremes. The waterproofing membrane can be most types of material suitable for flat roof applications. However, it is essential that it is installed by a qualified company, because it will be difficult to access this element if repairs are needed in the future. Bracknell Roofing’s specialist ‘living roof’ team is able to advise on which construction is most appropriate on each project.

Vegetation choice