Why a Green Roof?

Green roofs are widely recognised as an ideal way of improving air quality in cities. Planners and Councils are beginning to use extensive plantation for air purification in order to reduce carbon dioxide and increase oxygen in the atmosphere. Green roofs also make a significant contribution to reducing polluting air particles and compounds not only through the plants themselves, but also through the growing medium.

They are also increasingly being used in efforts to reduce and delay water run-off during times of heavy and prolonged rain, a fact that can be significant in reducing localised flooding. A recent study in Germany showed that during a 10mm rainstorm, whilst 200 litres of rainwater fell onto an 18m²green roof, only 15 litres actually passed from the roof to the ground. But given that some water does escape, it’s important to ensure that the waterproofing membrane does not have an adverse effect on the quality of water which is released from a green roof after rainfall.

When waterproofing green roofs the membrane itself must also be taken into account when thinking about the overall environmental picture. The method of manufacture, component chemicals and long-term environmental impact of the membrane itself can be as significant as the benefits of a bio-diverse ‘green’ roof.

A green roof requires a strong, durable and light membrane to line it. GRP (Glass Reinforced Polyester) is an inert material that can be used with ‘grey’ water harvesting systems and potable water. In service, it does not release any pollutants or chemicals.

Green roofs offer exceptional environmental and cost benefits to other forms of roofing, thus is becoming a mainstream option for commercial and domestic builds.

Why use Dryseal for waterproofing green roofs?

Dryseal is ideal for use as a waterproofing membrane under a “green” roof installation, for the following key reasons;

• GRP is environmentally sound and as there are no chemical emissions from the surface of cured GRP, it is ideal for a “living” roof. Dryseal GRP is safe to use with fresh water, so in turn is totally safe for use under a green roof.
• The unique way that the Dryseal system is jointed on site means that there is a chemical “cross-link” between the wet applied jointing resin and the resin used to manufacture the membrane and trims. This, in turn, means that joints are robust and homogenous with the membrane surface. Nowhere for a root to grow; no need for a root barrier.
• The impact resistance of Dryseal GRP means that the likelihood of damage during a sedum roof installation is minimised.

Partnered with Evergreens for the Lazylawn® synthetic green roof system, ideal for heavily trafficked and seating areas. Click the logo to download their brochure.

ANS Global for their living green roof GrufeKit which is a sedum system pre-grown in cassettes. Click the logo to download their brochure.

The Green Roof Organisation (GRO) is an independent not-for-profit Trade Association representing the UK Green, Blue and BioSolar Roofing industries.

If you want to hear more about using Dryseal for waterproofing green roofs, find our contact details here.