Blackdown semi-intensive green roofs provide the opportunity to increase the range of plant species used on the roof environment without having to specify an intensive system. Wildflower and drought tolerant planting can be used to great effect to provide increased bio-diversity and, at the same time, offer an aesthetically pleasing look.

Applications can include office, retail and residential blocks. Semi-intensive green roofs can also be used to blend in buildings within a rural setting.

Vegetation

A wide range of planting options is available, typically in the form of plugs, but can be larger if required. Drought tolerant wildflowers, herbs,
grasses and sedums are suitable, along with annual and specialist seed mixes that will replicate habitats such as chalk downland.

Key Features

Substrate

A Blackdown semi-intensive substrate is required for this range of plants. This offers good water holding capacity whilst still providing sufficient air and granulometric distribution to encourage strong root growth. Includes slightly lower levels of organic matter and nutrients than intensive substrates.

Waterproofing

Typical waterproofing options include suitable root-resistant bituminous membranes from the Derbigum and Euroroof ranges along with standing seam metal roofing.

Warranty

Warranties are available for the Alumasc waterproofing system used in the green roof build-up.

Click here to find out more about Alumasc Roofing System’s Green Roofs.

Intensive green roof systems are becoming more and more common in highly populated city centres, driven by sustainability and water attenuation requirements, along with the need to create usable space.

Intensive Green Roof Systems range from providing outdoor roof space at restaurants and office blocks, to creating ground-level landscaping above subterranean car parks at shopping centres or residential developments.

Vegetation

Can include lawns, shrubs, edible plants, perennials and grasses, small deciduous trees and conifers. Planting type and size determines the required irrigation system and soil depth.

Key Features

Substrate

A Blackdown intensive green roof substrate is required which contains a high level of organic matter in order to support a wide variety of plants and trees.

Waterproofing

Root-resistant waterproofing options include Hydrotech hot-melt structural waterproofing and suitable bituminous membranes from the Derbigum and Euroroof ranges.

Warranty

Warranties are available for the Alumasc waterproofing system used in the greenroof build-up.

Click here to find out more about Alumasc Roofing System’s Green Roofs.

Planting is all about the cultivation of plants which are wind, frost and drought resistant, require very little maintenance and are self-propagating. This type of vegetation will consist primarily of sedums, but can include herbaceous plants and grasses if the substrate depth and location are suitable.

Intensive: Hard and Soft Landscaping

Intensive green roof systems are often a mixture of hard and soft elements; this may include a variety of planting types, from semi-mature trees, lawns, shrubs and herbaceous borders to vegetable beds. Substrate depths can vary from 400-1500mm.
With this variety of planting an automated irrigation system is usually essential. Ponds, paving, lighting, seating and planters can all be accommodated to suit requirements.

Semi-Intensive: Wildflower Mat, Plugs or Seed

As the depth of the substrate is typically 150-200mm on a semi-intensive system, the range of plants that can be utilised on the roof includes a variety of wild flowers, sedum, herbs, grasses and alpines in the form of mat, plugs, seeds and bulbs.

A 40mm drainage layer is used to help increase and retain additional moisture for the plants. Semi-intensive green roofs can offer a more natural look to a planted roof. As with extensive green roofs, a semi-intensive green roof is not designed to be trafficked or to have a permanent irrigation system.

Bio-Diverse: Natural Habitat

Randomly graduated substrate, from 80-200mm, interspersed variably with shelter stones, aggregate piles, shallow pools and logs in conjunction with specialist seed mixes replicates specific habitats. The objective is to attract specific wildlife species, in accordance with the project’s bio-diversity plan.

Sedum NatureMat®

NatureMat® is a composite vegetated mat consisting of a biodegradable base layer, a specially formulated substrate layer and a 90% mature plant cover comprising 6 core and 13 randomly sown species (predominantly sedums), grown to maturity in Blackdown’s fields in Somerset. Laid onto a Blackdown substrate and drainage layer, NatureMat® is particularly suited to pitched or curved roofs.

Extensive Sedum Plug

A diverse selection of over 25 species of hardy succulent plug plants, supported by a minimum of 70mm of Blackdown’s extensive substrate and 25mm drainage layer, provides attractive plant cover with a range of colours, shapes, heights and flowering times and periods.
A variety of wild flowers, herbs, grasses, alpines and bulbs can equally be incorporated; varying the substrate depth to suit (70-150mm).

Extensive Sedum Hydro-plant

A mix of sedum cuttings, seeds, tackifier and fertiliser are applied through hydroplanting, onto the prepared Blackdown substrate and drainage layer. The plant cover will establish and grow (typically over 1 to 2 growing seasons) to deliver the long-term benefits of a green roof. Particularly suited to restricted budgets and large roof areas.

Click here to find out more about Alumasc Roofing System’s Green Roofs.

Blackdown specialises in plant production, component supply, full system installation and maintenance of extensive, semi-intensive, bio-diverse and intensive roof planting systems.

With nurseries in the Blackdown Hills in Somerset, and a long established background in horticulture, Blackdown offers clients expert advice on the most appropriate planting strategy for their project.

A holistic approach ensures the long-term success of Blackdown’s green roof installations, with the same care shown for plants on the roof as is shown during plant production at the nurseries.

An impressive track record of high profile projects alongside technical expertise and an innovative approach to overcoming problems, ensures Blackdown remains a market leader.

Grow – plants are cultivated in and tailored to suit the UK’s climate.

Supply – an extensive range of Blackdown green roof systems and components.

Install – cost-effective, high quality installations.

Maintain – affordable maintenance for long-term plant wellbeing.

Approvals – Blackdown green roofs comply with the UK’s GRO Green Roof Code of Best Practice 2014 and the German Landscaping and Landscape Development Research Facility (FLL) Guidelines.

A Single Source Offer

Grow:

By producing our own vegetation we can ensure that quality control procedures are maintained at each stage of
the production process. This ensures that only high quality vegetation is used on our roofs.

Supply

The Blackdown supply offer includes all of the components necessary for a high quality green roof system, delivered
throughout the UK. With our horticultural, roofing and contracting expertise, we appreciate the importance of on-time, in-full deliveries.

Install

Blackdown are able to offer a full installation service from simple extensive roofs to complex intensive roofs which can incorporate hard and soft landscaping, automated irrigation and lighting systems.

Maintain

Maintenance planning is essential to achieving a healthy plant community and a green roof that delivers its long-term objectives. With an increasing tendency for buildings to be procured on a lifecycle basis, Blackdown offers a single source, whole-life green roof solution: grown, supplied, installed and maintained by Blackdown.

Click here to find out more about Alumasc Roofing System’s Green Roofs.

Urban Heat Island Effect

Temperatures are known to be higher in urban areas relative to surrounding rural areas, due to the higher quantity of impermeable, reflective surfaces and increased population density.

Green roofs reverse this effect by returning moisture to the environment through evapotranspiration, reducing solar gain and improving air quality.

Stormwater Management

There is an increased need in the UK for Sustainable Urban Drainage Systems (SUDS).

The Flood and Water Management Act 2010 and recent increased flooding drives designers to consider and provide solutions to reduce the effect of construction on existing drainage systems.
Green roofs are recognised as a measure that can be used to provide a level of additional SUDS capacity.

Carbon Capture

CO₂ capture is one of the primary legislative drivers for including a green roof on a building.
As vegetation consumes carbon during photosynthesis, green roofs positively remove emissions, helping arrest climate change. Air pollution levels are also reduced by the green roof’s ability to trap harmful particulates and capture gases.

Habitat Provision

Green roofs can provide food, habitat, nesting opportunities or resting places for creatures displaced by urban development, such as spiders, beetles, butterflies, birds and other invertebrates.
Replacing lost habitat or creating areas of bio-diversity, potentially aids planning applications or helps contribute towards BREEAM.

Click here to find out more about Alumasc Roofing System’s Green Roofs.

UK Roofing Awards have become an industry-wide event that recognise and reward outstanding standards of workmanship and safety within the roofing industry.

The SSE Hydro, Glasgow

The competition, covering the full spectrum of 12 roofing disciplines, runs from September to January every year and thereafter a selection of projects are short-listed. In May, at The UK Roofing Awards Congress Luncheon, the winners are announced.

A range of criteria are taken into consideration by the judging panel including: degree of difficulty, aesthetics, problem-solving, Health and Safety, workmanship and environmental qualities. Alumasc Roofing Systems have two Green Roof projects shortlisted under the Sustainable Roofing categories, these projects are Greenwich University and the SSE Hydro in Glasgow. We are hoping to build on Blackdown’s success of last year when Contractor of the Year 2014 was won.

The £125million SSE Hydro is a state-of-the-art entertainment and sporting venue in Glasgow.
The Blackdown Intensive Green Roof system was specified by the architect as they were looking for a sustainable solution to help with the strong design features of the building’s entrance.

Greenwich Univeristy

Greenwich University officially opened in December 2014, the £78m new-build development is based in Stockwell Street within Maritime Greenwich on the UNESCO World Heritage Site. The project also included a new library, and features a series of terraced roofs, comprising 14 interlinked teaching gardens, forming the largest multifunctional roof space in London.

The Congress itself is made up of two parts: the Awards Lunch and the Evening Dinner Dance.

The winners will be announced on Friday 15th May at the UK Roofing Awards Luncheon at the Hilton London Metropole on Edgware Road. This year’s host is BBC’s Louise Minchin.

If you would like any further information please contact the National Federation of Roofing Contractors by clicking here.

Derbigum Olivine, an ecological roofing solution from Alumasc, has been used in the refurbishment of a Middlesex School. Opened in 1951, Mount Stewart Junior School in Harrow, is a community school for boys and girls aged 7-11.

Due to on-going issues with leaks and water ingress, Mount Stewart Junior School took the decision to re-roof the entire campus, comprising 7 roofs of various construction, totalling 2500m².

Alumasc and their registered contractor M&J Roofing were challenged with re-roofing the large roof areas in only eight weeks, to ensure minimum disruption to the school, its teachers and pupils. Budget constraints dictated that the solution needed to ensure not only waterproofing integrity, but also longevity, and minimal long-term maintenance costs.

Derbigum Olivine was the perfect solution which also offered additional ecological benefits, brought about by a naturally-sourced Olivine mineral layer. During rainfall, the Olivine membrane makes contact with CO₂ present in the atmosphere. This results in a chemical reaction, neutralising the CO₂ and providing a positive impact on climate change.

There were a number of detailing issues that had to be resolved, particularly regarding the sloping roofs which varied greatly from area to area. On some roofs there were areas of ponding water, and with the school’s budget not allowing for a tapered insulation scheme, Alumasc instead designed tapered gutters at the roof perimeters, to integrate with the new flat board insulation overlay and assist the drainage to the Alumasc gutters and downpipes.

Speaking about the installation, Richard James from M&J Roofing, added:

“The large barrel sectioned roofing area was very complex in its installation, especially when it came to fitting the insulation. Using Derbigum Olivine allowed us to achieve a good fit to this challenging area, and resulted in a highly respectable finish. We installed the first ever Derbigum Olivine system back in 2013 and, since then, the system has quite rightly grown in popularity. It not only offers unique CO₂ neutralising properties, but also has the longest product guarantee in the marketplace.”

Derbigum Olivine offers a market leading warranty of 40 years and is subject to minimal long-term maintenance requirements.

For further information or if you would like to discuss our flat roof systems call Alumasc Roofing Systems on +44 (0) 3335 771 500 or email: info@alumasc-exteriors.co.uk

Due to the EuroPHit project, a series of buildings from across Europe are to be retrofitted to Passive House Standards, this will include a mixture of residential and non-residential buildings using Passive House Components.

This EU project is to take place over the next 10 years and will lead to extensive improvements to the buildings such as economic efficiency, climate protection and repairs of any existing structural damage. In a large number of EnerPHit projects there has been up to a 90% reduction of heating energy demand.

Image Source: ECD Architects

Wilmcote House, Portsmouth consists of three 11 storey blocks that provides over 100 homes located in the central Portsea Island area of Portsmouth and owned by Portsmouth City Council. Built in 1968, this retrofit project would need to utilise the highest quality materials available to meet the Government’s economic targets and achieve the required 90% reduction in energy costs. The lifespan of the building, once refurbished, will also increase by another 50 years. Alumasc Roofing Systems has been selected to provide the refurbishment solution for over 1500m² of existing flat roof. The design brief is for the flat roof areas to be overclad using exterior grade plywood mounted on a lightweight steel framework, upon which the waterproofing system is to be installed. To achieve the goals of Portsmouth City Council from both a lifespan and environmental perspective, Alumasc have combined the qualities of the Derbigum and Hydrotech waterproofing systems to great effect. Hydrotech, a self-healing monolithic membrane with an unsurpassed track record of zero product failures in 50 years, will be installed to the newly laid plywood deck, and finished with the Derbigum Olivine, a CO₂ neutralising, high performance flat roof membrane.

Image Source: ECD Architects

The natural olivine (magnesium iron silicate) granules cause a chemical reaction in CO₂ in rainwater which converts it to harmless silicon dioxide (SiO₂, i.e. sand), magnesium carbonate (MgCO₃, i.e inorganic salt) and water. One square metre of Derbigum Olivine will neutralise approx. 1.75kg of CO₂, making it the optimum flat roof waterproofing choice for green specifiers. The roofing aspect of the project is to be conducted over 3 stages, one block at a time; stage one is due to commence in May 2015, second stage November 2015 and the final, third stage to be carried out in February 2016. The highly efficient and eco-friendly benefits of Derbigum Olivine combined with the guaranteed lifetime performance of Hydrotech made this the winning combination for the Wilmcote House project. This combined system offer also came with a market leading, comprehensive warranty package. The roofing aspect of the project is to be conducted over 3 stages, one block at a time, stage one is due to commence in May 2015, second stage November 2015 and the final, third stage to be carried out in February 2016. Other areas of the refurbishment also include new External Wall Insulation, various heating systems and highly efficient window systems.

For further information or if you would like to discuss Alumasc Roofing Systems for your projects call Greg Bourne on 07720 883 632 or email: bourneg@alumasc-exteriors.co.uk

The latest ‘Working on Roofs’ document from the Health and Safety Executive highlights the importance of edge protection systems when working on flat roofs.  Alumasc’s Guardrail lightweight edge protection system is ideally suited to address this issue.

Working on flat roofs

Work on a flat roof is high risk. People can fall:

•   from the edge of a completed roof

•   from the edge where work is being carried out

•   through openings or gaps.

Edge protection

Wherever anyone could fall, the first line of defence is to provide adequate edge protection to prevent a fall occurring. This should include or be equivalent to:

•   A main guard rail at least 950 mm above the edge.

•   A toe board and brick guard where there is risk of objects being kicked off the edge of the platform

•  A suitable number of intermediate guard rails or suitable alternatives positioned so that there is no gap more than 470 mm.

Sometimes a roof parapet may provide equivalent protection but if it does not, extra protection will be required.

Falls from the roof edge

Full edge protection (top rail, toe board and intermediate protection) is required whenever the work requires access within 2m of the roof perimeter. Edge protection is usually provided by an independent scaffold around the perimeter of the building or by barriers connected to the frame. An independent scaffold gives a higher standard of protection and a good standard of access along the structure. It also assists material loading and storage, e.g. when used with a fork lift/tele handler.

Where work is carried out 2m back from the roof edge and no edge protection is in place, you should mark out the working area and routes to it with continuous physical barriers. Tight supervision will be necessary.

Netting capable of providing edge protection in certain circumstances is now available.

Falls from the leading edge

Whatever system of work you choose, the presence of dangerous gaps is always a possibility as space is created to place the next leading edge sheet.

You must take precautions to prevent falls from these ‘leading’ edges. Nets and birdcage scaffolds are the preferred options in this instance. However, where these are not reasonably practicable you can consider using work restraint safety harnesses with running line systems or temporary barriers at the leading edge, e.g. trolley systems.

The Alumasc Guardrail range of lightweight edge protection systems is ideal for collective fall protection measures on flat roofs. Systems are supplied in kit form for easy handling and installation.

For more information on the Alumasc Guardrail range, click here, email roofing@alumasc-exteriors.co.uk or call 03335 771 500.

Source:  ‘Working on Roofs’ – Health and Safety Executive.

Alumasc has recently received RIBA approval for a new CPD, “Objective-driven specifications for Green, Bio-Diverse and Blue Roofs“.

The 45 minute presentation outlines the key factors to consider when designing a green roof including waterproofing, drainage layers, substrate and plant species.

Focus is also made on the variety of green roofs designs and how each system can offer benefits to meet drivers such as Regulatory Compliance, Carbon Capture, Ecological enhancement and amenity space.

Also included within the seminar is an introduction to BluRoof Stormwater Management Systems, a solution to SUDS. Detail is offered regarding design factors, system build ups, stormwater attenuation calculations and common concerns.

Henry Bareham, author of the new CPD, has received very positive feedback from architects who have attended the seminar. He says:

“The seminar has been designed to offer specifiers a guide to the range of green roof design options that provide solutions to the variety of legislative drivers and employers requirements.”

“BluRoof is a relatively new concept to many designers, the seminar offers an introduction to a system that provides a solution to the stormwater runoff design constraints faced by Architects and Drainage Engineers.”

If you would like any further information on the seminar or to book please click here.

If you would like any further information Alumasc’s Roofing Systems call us on 03335 771 500