Introduction

Adrian Culling, Technical Manager for Blackdown Greenroofs has been working at Blackdown since 2008, and has priced a lot of green roofs in that time, but recently it seems that the majority of specifications that come cross his desk are for sedum mat – why is that? In the past Blackdown regularly specify and price for sedum plugs, both systems offer advantages and disadvantages, in this article he’s tried to summarise these as briefly as possible below.

Producers

It is very difficult for any grower to guarantee that the number of species within each square metre is supplied. The grower is more likely to state the mat will be made up of a combination of their listed species. Blackdown state that they have 6 core species and additionally 13 randomly sown species present in NatureMat®. Some sedum mat growers on the continent produce mat with as little as 4 species within it.

This is because some European and Scandinavian markets prefer to have fewer species within their sedum mat. With a plug plant system, the number of species can be clearly specified by m2. It is easier to introduce additional wildflower species into a plug system than to try and ‘inter-plug’ a sedum mat system.  Over-seeding a sedum mat system does not work, whereas, over-seeding a plug system will work i.e. over-seeding wildflower seed with sedum plugs.

Installation

Aspect

With a plug planted system the aspect of the roof i.e. its orientation and therefore the amount of sunlight or shade that the greenroof receives, can to some extent, be compensated for by the species of sedums chosen to be included on the roof. A blanket system does not offer this degree of flexibility when it comes to dealing with shaded areas.

Customization

Blackdown grow over 25nr different types of sedum and sempervivum in plug form – this enables Blackdown to customise the composition of planting on a greenroof.  Given sufficient time Blackdown can grow to order additional species of sedums – for further information contact us.

Blackdown would only recommend that a sedum plug system be installed up to a max pitch of 25 degrees, above this a sedum mat system should be specified.

Aesthetic

The greater variety of plug plants that are included within a plug system will only enhance the aesthetics of a green roof. This will help to prolong the flowering period and increase the visual interest of the green roof compared to NatureMat®, which has few species included within it.

Installation time & cost

A sedum plug system will take slightly longer to install compared to a mat system, however, the overall price should be cheaper due to the fact that there is less plant material being installed on the roof i.e. the GRO guidelines state that a mat system has a min of 75% plant coverage, whereas, a plug system will have between 5-10% coverage on installation.

Coverage

Blackdown NatureMat® typically has a sqm coverage of 90-95% upon installation. The establishment of a plug system will take approx. 6-9 months to get to 75-90% coverage.  However, this depends upon the month of planting, level of maintenance and irrigation applied.

Lifting and Offloading

No matter which system is ultimately chosen, the materials still needs to be lifted to the roof and distributed – and as each system has the same weight and depth there is little or no advantage when it comes of on-site services.

Establishment and Maintenance

Temporary Irrigation Temporary irrigation requirements will be the same for either system i.e. they’ll be required for a period of 6-8 weeks or until the plant material is fully established. However, if the system is correctly specified & installed, neither system will require additional irrigation once the plants are established.

Maintenance

Maintenance is often considered an optional extra – this is simply not the case. As with all plant material a little maintenance goes a long way to getting the best out of the system. Maintenance requirements will be the same for either system.

Conclusion

Blackdown Greenroof sedum plug systems offer a cost effect alternative to the NatureMat system whilst providing the benefits of increased numbers of species and better aesthetics. Both systems offer very tangible advantages to customers and specifiers, so perhaps we should give the humble sedum plug more room on our roofs.

If you have a project that may require our products please email any drawings, literature or enquiries to contact@alumascroofing.co.uk

In order for you to plan your capital works programs effectively you will need to obtain stock condition information. This can only be kept updated accurately by carrying out field surveys.

This is where our knowledge and expertise can assist you.

We operate a national service of experienced area technical managers that can assist you to ensure your stock is up to DHS & HHSRS standards.

We also offer budget costing so future funding and/or investment can be identified and planned.

For further information about our products and services please CLICK HERE or call 03335 771 500.

A ‘single source’ solution can be more beneficial and will benefit the customer as this provides a more efficient supply chain. The ‘single source’ solution also helps in reducing turnaround times and overall costs.

Another major benefit is the guarantee of material working well together and to a higher, tested standard. For example, Alumasc Roofing Systems can provide the full system from vapour control layer to the cap sheet, whereas sourcing the various system components from a multitude of suppliers can cause unforeseen problems when obtaining warranties.

For further information about our products and services please CLICK HERE or call 03335 771 500.

Both guarantees and warranties are legally binding contracts. This means there is no way a manufacturer could refuse to fix your problem if it falls within the terms and conditions of the agreement.

Alumasc offers an unrivalled and comprehensive choice of extended warranties of up to 35 years covering both product and installation.

A range of Alumasc backed warranties are available, supported by public and product liability insurances with a total indemnity limit of £50 million.

Third party insurance backing giving cover against latent product defects is available via PRA regulated insurance brokers subject to independent final inspection, documented compliance with an agreed maintenance schedule and pre-payment of the relevant premium.

NB: Warranties are only offered on waterproofing projects that have been installed by Alumasc Registered Contractors in accordance with the relevant project specification, codes of practice and Alumasc installation instructions ruling at the time of application.

Our customers understand the importance of warranties when it comes to roofing systems due to the fact that the costs of replacements and repairs can be extremely high. Alumasc aim to provide their customers with a high level of peace of mind.

For further information relating to warranties for your specific project please contact us at our St Helens office or speak to your local Area Manager directly.

Our product brochure provides more in-depth information – please CLICK HERE or call 03335 771 500 to request your copy.

To reduce both cost and disruption it is essential to select a system that will offer robust long-term performance. It’s also advisable to select a system that can adapt to future changes such as the introduction of new plant on the roof for sustainability benefits for example.

20 year warranties are commonplace but these can be increased up to 35 years for complete Alumasc system applications comprising of the full roofing system build-up and insulation along with all of the associated accessories such as rooflights, trims, outlets, aluminium copings etc.

Independent insurance backing for up to 20 years is available from Alumasc on selected projects and systems.

Five yearly post-installation inspections can be provided under our Alumasc Promise Warranty that is also available on selected projects. This ensures the additional security of regular maintenance and continuity of waterproof integrity throughout the warranty period.

For further information about our products and services please CLICK HERE or call 03335 771 500.

The key to a roof refurbishment to an existing roof is to be able to offer a solution that caters for the needs of those that are currently working within the building.

Approved and qualified contractors

In order for the selected roofing systems to be installed to the highest of standards and to prevent roof failures it is imperative to ensure that the installers are fully trained for the specific roofing system they are installing.

If the roofing system is installed by registered contractors this ensures that all processes used are within the official criteria thus qualifying the roof system with a comprehensive warranty.

Alumasc Roofing Systems have registered contractors that can provide the highest levels of installation available – with warranties of up to 40 years we can provide the highest levels of peace of mind.

Avoid hot works where necessary

To eliminate the potential fire hazard of gas torching techniques associated with high performance bituminous membranes (and to comply with insurance requirements) the safe option would be to select flame-free application in the vicinity of combustible materials. Methods include using self-adhesive or thermo-adhesive membranes which avoid direct flame contact with the substrate. Cold-applied liquid systems can be used for sensitive detailing areas and also complete roof areas if desired.

Avoid bad odours and fumes

To avoid the creation of bitumen fumes and to avoid the use of solvents in sensitive or restricted areas, self-adhesive membranes requiring only minimal hot-air welding may be installed, or alternatively, solvent free, low odour cold-applied liquids may be used.

This is especially prudent when working within schools, hospitals and some built up office areas.

For further information about our products and services please CLICK HERE or call 03335 771 500.

An initial discussion to understand your requirements is crucial to the success of the project/scheme.

Obtaining information on historical defects and resident issues are also major factors. Stakeholder information regarding leaseholders and tenants can also be of great value.

Understanding their circumstances and gaining their trust and support is often vital to the success of a project.

We can advise you of current and upcoming legislative requirements such as energy improvements through improved insulation.

For further information about our products and services please CLICK HERE or call 03335 771 500.

SURVEY

The initial purpose of our survey is to establish the current condition of the existing waterproofing and substrates. Core samples are taken during the survey to provide factual and accurate information.

Based on our findings we can establish whether the existing waterproofing system should be removed or overlaid.
Items such as drainage, substrate suitability, abutments, flashings etc. will all be inspected so an accurate, comprehensive scope of work can be created. This will help with providing cost transparency.

REPORT

This will detail all our findings, highlighting existing defects and the results of the core samples taken. The report concludes with a summary of our findings and recommendations moving forward.

We also suggest works to associated items such as lightning conductors, abutment detailing and edge protection etc.

For further information about our products and services please CLICK HERE or call 03335 771 500.

Bridgend County Borough Council’s 40 year-old Celtic Court building got a valuable new lease of life when a fully integrated Alumasc waterproofing system was installed – along with multiple products from Alumasc Exterior Building Products; external wall insulation and render from Alumasc Facades; and rainwater goods from Alumasc Rainwater.

The Local Authority renovated the building, for use in partnership with other Public Bodies, after the old waterproofing system had deteriorated significantly over the years and received multiple ad hoc repairs to extend its serviceable life. Bridgend Council selected Alumasc and their Carmarthen-based registered contractor, Central Roofing, to provide an effective, long term refurbishment solution by waterproofing the roof areas of the building.

Central Roofing completely removed the existing waterproofing system back to the deck where repairs were carried out to the concrete & screed.

They installed a new Euroroof vapour barrier to provide some immediate protection against the elements and fitted Alumasc PIR insulation, incorporating tapered gutters, to help the roof drain better. A fully engineered insulated felt render system was then laid, onto which they applied a non-penetrative Aluminium capping system.

New Aluminium rainwater downpipes were also installed, and the waterproofing project was completed when Central Roofing applied the Euroroof waterproofing system – which comprised a felt underlay and Euroroof MG3/4 capping sheet, which came with a 25-year System warranty.

Bridgend County Borough Council’s Paul Avo said: “Alumasc and their installer, Central Roofing, have been excellent throughout. The thoroughness of their initial site survey and the design solution they proposed were impressive, and the quality of the work undertaken was first-rate”.

Alumasc’s market leading Swisslab External Wall Insulation was used to provide the exterior walls with a highly efficient insulated system and final finish. The combination of these various Alumasc products gave Alumasc the opportunity to provide the full envelope, single source package for this project.

If you have a project that may require our products please email any drawings, literature or enquiries to contact@alumascroofing.co.uk

A new Alumasc Euroroof waterproofing system has been installed on nine refurbished roof areas at Brownmead Primary Academy, providing an effective long-term solution for this Junior and Infant school in Shard End, Birmingham.

Following numerous historic patchwork repairs to the school’s previous waterproofing system, Educational Support Services West Midlands (ESSWM) commissioned Alumasc to perform a detailed site survey of all flat roof areas. The resulting Roof Condition Report stated that the original system integrity was seriously compromised, with high levels of entrapped moisture identified within the insulation to the main roof area. Varying levels of deterioration across the roof areas were recorded and clear recommendations for how these would be addressed were given within the site specific specification.

ESSWM appointed approved installer Clarendon Roofing to refurbish 1,200m2 of existing roof areas with Alumasc’s Euroroof BUR (built-up roof) waterproofing system, to deliver high-performance waterproofing and a fully engineered Cut to falls insulation scheme. All internal drainage locations were also to be refurbished with the Roof Pro PRODRAIN refurbishment RWO (Rain Water Outlet), to ensure effective water management was maintained throughout. The waterproofing system also included the refurbishment of the original roof lights with Alumasc Type A Roof lights – to provide a fully Part L2B compliant system.

The first step was the complete strip and removal of the deteriorated waterproofing system from the concrete screed beneath. Appropriate surface preparation to the screed was then undertaken prior to the installation of the Euroroof Torchtite Vapour Control Layer; providing immediate protection against water ingress into the main hall, classrooms and kitchen below.

Areas identified as suitable for “up-grade” received necessary preparation works and surface conditioning, prior to the application of the proposed specification.
The Alumasc Cut to falls scheme was designed to enhance and overcome the existing design falls to each respective roof area. The design brief for the drainage plan was to utilise the existing drainage locations, remove standing water from all roof areas and meet the target u-value of an average 0.18W/m2K.

Clarendon Roofing then applied the Euroroof waterproofing system, which comprised a Hi Ten Universal Torch-applied underlay and Euroroof MG4 capping sheet.

During the material installation the areas of potential risk, up-stand to cladded elevations, were identified and detailed in a “Flame Free” manner to mitigate potential risk – as set out in the Alumasc “Flame Free” policy document.

Effective planning and teamwork was essential, as all of the work had to be completed without disrupting the functioning of this junior and primary school for 4-11 year old children from the Shard End and Castle Bromwich areas of Birmingham.

ESSWM Managing Partner Scott Timmins commented:

“From the outset, Alumasc have been excellent. The thoroughness of their initial site survey and the design solution they proposed were impressive, and the quality of the work undertaken by their approved installer, Clarendon Roofing, was first-rate”.

Mr Ashley Winters, Head Teacher at Brownmead Primary Academy added: “I am delighted we now have a brand new waterproofing system which will help protect the school from the elements for years to come. Importantly, even though some of the work had to be undertaken during term time, there was no material disruption to the safe and efficient running of our school either”.

If you have a project that may require our products please email any drawings, literature or enquiries to contact@alumascroofing.co.uk