City flooding reduced by green roofs

Commercial Green Roof Installation

A growing number of organisations and businesses are realising the benefits of installing a green roof on their premises. The benefits are not just environmental, although that is a good reason on its own, but also economic and practical. From reduced energy costs and other building efficiencies to more practical advantages such as water attenuation to reduce localised flooding and increased staff wellbeing.

If you are looking to expand your commercial premises or make changes to the building or buildings you operate from then a green roof can also help with planning, BREEAM and other permissions.

As highly experienced commercial green roof installers, The Urban Greening Company can provide you with everything you need to get your green roof installed from start to finish.

Installing a Commercial Green Roof

At The Urban Greening Company we have many years’ experience installing all types of commercial green roofs, from small office terraces to large scale sedum roofing covering 1000’s of square metres. The type of roof you will need or be able to install will depend on a range of factors. When you contact us one of our project team will guide you through the options and assess the most suitable solution for your roofing. We can discuss the practical aspects and go over any permissions or surveys you may require as well discuss any environmental or sustainability targets you may be trying to meet.

Benefits of a Commercial Green Roof

green roof reduces Co2ENERGY EFFICIENCY 

Soil and vegetation are an excellent insulator, reducing heat loss in the winter and cooler months while reducing solar heat gain (the increase in temperature within a space or building caused by the sun) during the summer and hotter periods. This has a direct impact on heating and cooling costs and is backed up by research from many countries and organisations.  Research from green roof leaders Germany have shown savings of around 2 litres of fuel oil/ m2 of green roof that is installed.

green roof noise benefitsREDUCED NOISE POLLUTION

Research has shown* that noise pollution is also reduced on buildings and units with green roofing. This can be especially significant in urban areas where residential and commercial premises may be in close proximity to each other. The soil and vegetation acts as a noise dampener that increases with thicker soil and planting.

* “Sound reduction by vegetated roof tops (green roofs): a measurement campaign” and “Acoustic effects of green roof systems on a low-profiled structure at street level” Are 2 such examples but there is a growing library of positive research examples.

green roof storm water mitigationWATER ATTENUATION

Rain and storm water runoff are becoming a problematic issue, especially in urban and built-up areas where many commercial and industrial premises feature large areas of hard standing for cars and other transport. Green roofs are very effective at reducing the amount and speed of the water that runs off what are often large commercial roof areas. Combined with a “Blue Roof” type roof install, storm water can be significantly and effectively managed.

green roof biodiversity benefitsINCREASED BIODIVERSITY

Green roofs have become an excellent weapon against lost biodiversity and can have a direct positive impact on how any planning or building permission is viewed. As our understanding of the impact buildings and built-up areas are having on nature increases, it is becoming clear that green roofing can provide excellent habitats for birds, insects and specific plant species that may otherwise have been lost or impacted by commercial development plans.

green roof pollution busting benefitsCLEANER AIR

An increasing amount of research*  has shown that green roofs and urban greening in general can have a measurable impact  on air quality and pollution in the environment, particularly in urban and commercial environments.

* “Modelling studies found that green roofs can result in up to a 30-57 per cent reduction in air pollution.”  cited from “Green walls, roofs and screens can improve air quality in street canyons, finds a new review” – University of Surrey News.  See also “Mitigation of urban particulate pollution using lightweight green roof system”  Many other examples also available.

Types of Commercial Green Roof

There are several types of green roof you can install on a commercial premises:

INTENSIVE GREEN ROOF

An intensive green roof is essentially a garden or park type area on a rooftop, and they are often designed and intended to be enjoyed or used in person. When installed these roofs have deeper soil layers and can support a wide variety of plants, including grass (as you would expect), shrubs, and even small trees. These are popular for large commercial roof installations such as on factories and large multi-level retail areas, and also popular for hotels and care home podium deck type constructions.

EXTENSIVE GREEN ROOF

An extensive green roof is a type of green roof designed to be lightweight and low maintenance. These types of living roof are much more common and are comprised of primarily low-growing, drought tolerant plants such as sedum and hardy grasses or herbs.  This type of green roof also includes wildflower and biodiverse green roof types. There are a wide range of systems available to facilitate the installation of this type of roof and they are suitable for many types of commercial and retail premises.

INTERMEDIATE GREEN ROOF

An intermediate green roof type that can include characteristics of both extensive and intensive roofs.

 

◈◆◈◆◈◆◈◆◈◈◆◈◆◈◆◈◆◈

Installing a Commercial Green Roof

Green roof installation can be carried out using a variety of different systems from built in place custom installs to modular tray systems (More normal on a domestic green roof), but they all follow the same basic installation steps.

  1.  EPDM Roof waterproofingWaterproofing & Protection: The roof must be clean and watertight before commencing anything else. As the roof is probably a flat roof it will have been exposed to water and UV rays for far longer than a normal pitched roof so it will need a thorough inspection before anything else can happen. Any weak points or damaged areas will need to be repaired and made good. An additional waterproof coating maybe added such as a waterproof rubber sheet (EPDM). The existing drainage will need inspecting and possibly updating.
  1. Root Barrier: In most cases but especially where bituminous waterproofing is used, a “root barrier” will be installed. This is a tough, multilayered and puncture resistant sheet or similar to protect the watertight roof layer from the roots of whatever is going to grow above it.
  1. Drainage and Filtration: Drainage mat is a lightweight layer that does exactly what its name suggests. It allows excess water to drain away from the plants and channels it into the roof’s own drainage system which will be installed around the edge of the roof.  The drainage layer will also include a filter fleece which simply prevents soil and other debris clogging up the filtration. This could cause waterlogging that can kill-off some of the roof planting.
  1. Gravel Edging: A gravel edge will be added to the roof to facilitate efficient drainage and to keep the plants and soil from fouling the guttering, downpipes and eaves of your premeses. Consequently, it also stops the soil from being washed away from the main planted roof area.
Laying filter fleece and drain at Colchester

Laying filter fleece and drain at Colchester with wide gravel edging visible.

  1. Substrate: The substrate, or growing medium, supports the growth of the grass or plants that will make up your green roof. A substrate is a soil alternative designed to be lightweight, so as not to put too much strain on your roof,  yet nutrient-rich, providing an ideal environment for the plants to thrive.
St Botolph Without Aldgate Community centre roof turf ready to lay

Light weight Substrate down and green roof turfs stacked visible behind ready to be laid over it.

  1. Vegetation: The final and most visible part of your green roof is the vegetation or plants. If a Sedum roof is being installed then sedum blankets will often be used. These are rolled out on top of the substrate just as if you were having a lawn returfed. If many different plants are to be used, such as for an “Intensive” style green roof then pre-planted modular interlocking trays may well be used instead. BOWA medical with Sedum green roof installed

Once complete the roof will be watered and fed. In some cases, it may be recommended to add an irrigation system. An ongoing maintenance plan will also be advised on to ensure the roof establishes and thrives. We will also arrange to return after a certain amount of time to check on everything and sort out any teething problems or unforeseen issues. At this point any struggling plantings will be attended to and, if necessary, replaced.

◈◆◈◆◈◆◈◆◈◈◆◈◆◈◆◈◆◈

SOME REAL WORLD COMMERCIAL GREEN ROOF EXAMPLES

Some examples of our Commercial Green Roof Installations and remedial work are below. Please contact us if you would like any further information or to discuss a project with us.

green roof on lodge at Melbury Vale Winery
, ,

Green Roofs and Sustainable Wine