August 2012: Prospects in the flat roof market may not exactly be buoyant currently; but one sector where growth (pun intended) is absolutely expected – green roofs. This is currently a very small part of the market but that’s widely expected to change. We asked quantity surveyors, architects, roofing contractors, general contractors, main contractors and they all agreed. That doesn’t often happen… so it’s worrth looking at some of the underlying drivers in play here.
We constantly hear that price is the primary consideration and of course it’s always important. However, there are Local Authorities that are making a green roof a pre-requisite of planning consent on non-domestic buildings. We’re not talking about small authorities, either: we’re talking about London boroughs and major provincial cities like Sheffield. Our research shows that this will become even more prevalent on major projects.
So… what is a green roof? It’s not as simple to define as you’d think. There are three main types: intensive, semi-intensive and extensive. Basically an intensive roof requires deeper soil, supports more plant life and requires more maintenance; whereas an extensive roof is sedum and virtually maintenance free. There’s a good explanation here.
Inverted (upside down) roofs are a common choice for green roofs – because the insulation protects the weatherproof membrane and provides an additional protective barrier. Our own Jablite Flat Roof Inverted (FRI) has been used on this rather pretty roof near a large sports stadium in Stratford, East London.
Insulation for inverted roofs needs low water absorbency – less than 1%. Jablite FRI delivers this and is also A+ rated – important to designers of green roofs!