Green Roofing

High Performance Green Roof Systems

Alltech Roofing understands the growing demand for sustainability in construction for the benefit of the environment. Further to the introduction of BREEAM (Building Research Establishment’s Environmental Assessments Method), green roofing is being increasingly specified as a more positive step towards sustainability.

Alltech Roofing offer a full range of green and bio diverse roofing systems that include extensive, semi-intensive and intensive systems. The purpose of a bio-diverse roofing system is to harmonise with flora, fauna and local eco systems. There is a range of important components that make a bio-diverse roof work efficiently; namely seed mixes and mulch preservations, logs, boulders, aggregates, silts and cohesive soils, crushed brick, contours and mounds, concrete mixes, crevices and boxes for insect and bird habitat and plug planting with a wide option of species such as Agrimonia eupatoria, Agrimony, Anthyllis vulneraria and Kidney vetch.

When offering an extensive or intensive green roof system, it is pivotal to provide full compliance with BREEAM in addition to achieving the level of aesthetics required by the client and end user. Alltech's green roof services range from intensive bespoke roof garden installation with options of shrubs, plants and turf finishes and irrigated systems where required. Extensive roof areas require less water and include plug planting or a pre grown sedum carpet which provides an instant carpet effect. Example of species are Centaurea nigra, common knapweed, Clinopodium vulgare, wild basil, Echium vulgare, viper’s bugloss, Galium verum, lady’s bedstraw and Hypericum perforatum.

Green and bio diverse roof build up comprises waterproofing layer including root barrier, drainage and water retention mat (manufactured from recyclable polypropylene), filter sheet, extensive substrate and sedum plug plants or sedum carpe. All planting should be planted between spring and autumn, and in periods of drought or dry weather the system is designed for water stored in the retention mat to diffuse up through the substrate and feeds the plugs or sedum carpet.


Semi Intensive is to support a more demanding planting theme such as plants and shrubs which require higher water content. Therefore a 60mm water retention mat is required with approximately 150mm semi intensive treated soil. Intensive Green Roofing requires a 60mm water retention mat and approximately 450mm intensive treated soil. Planting designs on an intensive green roof system will normally be designed by a specialist landscape consultant. This system requires full irrigation to provide the required levels of water to maintain the planting design. The planting plan whether turf on lawn areas or other species of plants will dictate the depth of soil.