THE DUCKwww.kempersystem.co.uk

Liquid Waterproofing and Roofing Systems UK Issue 3

Visit our stand at:www.ecobuild.co.uk

Also in this issue:

Major Pharmaceutical HQ (U)

Guildhall Business Library (U)

AGC Chemicals, Lancashire (U)

Barr Beacon School, W Mids (U)

Richmond Park Golf Club (U)

ew Millennium Seed Bank (U)

MIT Dome, Massachusetts (USA)

Miller Park Fountain, Preston (U)

Planting the Seeds of a Successful

Green Roof Specification

Florida University (USA)

Huddersfield University (U)

As the National Theatre prepared to raise the curtain on its 50th anniversary season, KEMPER SYSTEM ensured that its’ Grade II listed building continued to perform by providing the waterproofing membrane for a major refurbishment project.

Famously described by Prince Charles as a ‘clever way of building a nuclear power station in the middle of London without anyone objecting’, the National Theatre is almost as famous for its architecture as it is for the quality of the productions it stages. Located on the South Bank of the Thames, it’s a pretty hard building to overlook, whatever your opinion of its modern concrete structure, and has been Grade II listed since 1994. For the team that manages the building, therefore, there is a significant responsibility to maintain the structure as a piece of national heritage, a public building and a busy workplace.

Operational Requirements

One of the architectural features that make the National Theatre such an unconventional design are the distinctive terraced balconies that form its rectangular concrete silhouette. These provide both public walkways and roofs for offices below so when their original asphalt surfaces started failing, resulting in leaks, a solution needed to be found quickly. The re-waterproofing was carried out as part of the National Theatre’s £80 million refurbishment programme but one of the main specification criteria was finding a way to complete the works without any business interruption implications and specialist contractor Cobsen-Davies was brought in to advise on the best approach.

Explains Tony Ward from Cobsen-Davies London Ltd: “While the existing substrate was asphalt, the use of hot

London, (UK)

EMPER SYSTEM Takes Central Stage at the National Theatre

works to replace the roof/walkway surface was out of the question as the building had to remain operational. Stripping out the existing substrate was also something we wanted to avoid as this would prolong the programme and generate waste, which adds to costs and creates logistical problems in such a central London location. A cold liquid-applied waterproofing membrane was clearly the most appropriate solution as this could be applied to the existing roof substrate on a section by section basis, ensuring that only small sections of the surface needed to be inaccessible at any given time.”

Business as Usual

To enhance the ‘business as usual’ specification still further, Tony Ward recommended EMPEROL® 2-PUR from EMPER SYSTEM, a solvent-free cold liquid-applied waterproofing membrane that is often specified for occupied buildings thanks to its odour-free characteristics.

Stuart Hicks from EMPER SYSTEM comments: “While a roof refurbishment does not always impact on staff even in an occupied building, the design of the National Theatre building meant that the re-surfacing work was taking place both above and below the office and workshop windows and near public access areas. Solvent-free EMPEROL® 2-PUR was, therefore, a big advantage as this could be installed on top of the existing substrate in a single process without any nuisance odours, while providing a high level of performance and a BBA certified service life in excess of 25 years.”

Project: 1,200m2 RefurbishmentMaterials: KEMPEROL® 2K-PUR Liquid Waterproofing

THE DUCK Magazine for Liquid Waterproofing and Roofing Systems 32

High Wycombe, (UK)

London (UK)

EMPEROL® 2-PUR eeps Guildhall Library In Business

A major multinational medical devices, pharmaceutical and consumer packaged goods manufacturer was able to remain operational at its High Wycombe UK headquarters throughout an extensive roof refurbishment project thanks to the solvent-free KEMPEROL® 2K-PUR waterproofing membrane from KEMPER SYSTEM.

The company’s extensive office building has a complex 13,000m2 flat roof split across many levels, including a plant room roof, multiple balconies and an internal courtyard. The existing asphalt roof had reached the end of its service life and needed to be replaced. The client stipulated that there should be no business interruption during the works and specified the need for an odourless system. Specialist contractor, Concept Roofing, responded with a warm roof upgrade

and solvent-free liquid waterproofing membrane from KEMPER SYSTEM, KEMPEROL® 2K-PUR for the extensive project that was shortlisted as a finalist in the Liquid Waterproofing category of the Roofing Awards 2013.

The original inverted roof design was upgraded to a warm roof, improving the thermal performance. KEMPER’s KEMPERTHERM FR insulation board was selected due to its dense closed cell structure and interlocking tongue and groove joints. The joints reduce cold bridging and give a rigid base creating a smooth, flat surface with stable joints with minimal increase in height.

KEMPERTHERM FR insulation has a 3mm reinforced facing that can be used on areas subject to greater point loading or more frequent traffic. This offered a cost-effective solution for the more frequently trafficked areas and avoided the labour and material costs of an additional plywood strengthening layer.

The Concept team began by stripping off the existing inverted roof components, down to the old asphalt which was then prepared ready for the new KEMPERTHERM insulation board. KEMPERFIX fast curing polyurethane adhesive was used to bond the insulation to the asphalt, itself now acting as the vapour control layer for the build-up. Once primed, the KEMPEROL® 2K-PUR waterproofing was then applied directly to the insulation board. KEMPEROL® is applied ‘wet-on-wet’ with the resin saturating a polyester reinforcement fleece. The resin cures to create a membrane which is immensely strong, yet flexible, durable and tear resistant. This application method provides total

integration of the base and surface build-up into a single chemically bonded seamless membrane, thus avoiding the weaknesses associated with multiple coating systems.

To complete the installation, Concept roofing created anti-slip walkways on the roof and the courtyard areas with KEMPER SYSTEM’s TC resin and bespoke specification coloured quartz. This gave the ‘red carpet’ effect on the roof, with decorative grey quartz being used in the courtyard areas. Finally, the quartz surface was sealed using KEMPER SYSTEM’s silk-matt Eco Finish.Frank Smith from Concept Roofing comments: “KEMPER SYSTEM’s KEMPEROL® 2K-PUR solvent-free waterproofing membrane not only provides clients with an eco-friendly solution, its odour-free formulation also makes it ideal for occupied buildings as there are no nuisance odours. This project upgraded the thermal performance and waterproofing protection of the roof in a fast, fuss-free programme.”

At a Glance:

Project: 13,000m2 Roof Refurbishment and Warm Roof UpgradeMaterials: KEMPERTHERM FR Insulation KEMPEROL® 2K-PUR Liquid Waterproofing STRATEX Warm Roof SystemContractor: Concept Roofing

High Wycombe, (UK)

EMPER SYSTEM Rolls Out the Red Carpet for Major Pharmaceutical Firm HQ

EMPER SYSTEM Rolls Out the Red Carpet for Major Pharmaceutical Firm HQ

KEMPER SYSTEM’s KEMPEROL® 2K-PUR waterproofing system has been used on a further phase refurbishment of London’s historic Guildhall, this time to provide a new roof surface for the Guildhall Business Library.

The scheme follows the recent roof refurbishment of the Guildhall’s West Wing by main contractor Linbrook Services Ltd and involves overlay of a 300m2 asphalt roof featuring 56 pyramid rooflights. The brief to roofing contractor, A&L Roofing Services, was to

complete the project within a six week programme, during which the library had to remain fully operational.

Guildhall selected EMPER SYSTEM’s EMPEROL® 2-PUR system for both projects as its solvent-free formulation enables an odour-free installation, preventing any nuisance odours affecting staff or visitors to the building. The cold liquid-applied system also made it possible to apply the waterproofing membrane precisely to the upstands and drainage channels of the 56 pyramid rooflights, which are located extremely close together in the central area of the roof, whilst seamlessly incorporating the entire roof.

At a Glance:

Project: Guildhall Business Library300m2 asphalt roof56 pyramid rooflights

Materials: KEMPERTEC® Primer KEMPEROL® 2K-PUR

Waterproofing SystemContractor: A&L Roofing Services

The installation team began by cleaning and preparing the asphalt surface which had begun to blister and split. EMPER SYSTEM’s EMPERTEC primer was then applied to stabilise the substrate and provide a chemical key for the waterproofing resin. Once this had cured, the waterproofing membrane EMPEROL® 2-PUR was installed onto the roof. Applied in a single process, the EMPEROL® resin saturates a non-woven reinforcement fleece and cures to form a monolithic membrane that is UV stable, extremely tough, flexible and tear resistant, that bonds directly to the substrate. EMPER SYSTEM’s non-woven reinforcement fleece was cut to size and shape on site to enable the meticulous detailing and protection of the most vulnerable parts of the roof around the rooflights, outlets and upstands as well as the flat roof areas of the roof.

Lee Lane from A&L Roofing Services comments: “eeping the library open during the six week programme meant

that the old rooflights had to remain in place while the job was done before being replaced with new pyramid rooflights at the end. This made for a very challenging project which could really only be delivered by a cold-liquid applied system that can be applied accurately to the multiple facets and contours of the complex detailing. The fact that the EMPEROL® 2-PUR system is eco-friendly as well as odour-free was an added bonus for Guildhall, and kept the refurbishment in line with The City of London’s sustainability aims.”

THE DUCK Magazine for Liquid Waterproofing and Roofing Systems 54

Richmond (UK)

EMPER Helps To Create The Green On 19th Hole At Richmond Golf ClubKEMPER SYSTEM’s KEMPEROL® V210 waterproofing membrane has played an important role in the development of a new sustainable club house at Richmond Park Golf Club. The new facilities incorporate a number of green technologies in order to achieve a BREEAM rating of excellent.

Distinctively shaped like a bird in flight, the roof of the new club house has been designed to complement the building’s surroundings and maximise its thermal efficiency. The building boasts a green roof over a warm roof build-up, which uses acid turf from the Royal Park at Richmond allowing the gently sloping building to blend into the rolling landscape of the course.

Gary Millsom of roofing contractor, Garhigh, said, “In order to ensure the roof remained watertight, EMPER SYSTEM’s seamless liquid waterproofing system EMPEROL® V210 was selected for its FLL certified root-resistant properties, durability and proven performance in green roof developments.”

Jon Dummett, Head of Golf for Glendale Managed Services explains: “The £2.5m investment into the clubhouse is part of our long-term commitment to improving the facilities at Richmond Park Golf Course. Working in conjunction with The Royal Parks, an important aspect of this project is sustainable building design and the use of renewable energy sources. The response from

to the exact contours of the details on the roof for excellent leak-free waterproofing integrity.”

At a Glance:

Project: AGC ChemicalMaterials: KEMPERTEC® D Primer; KEMPEROL® V210

Waterproofing SystemContractor: Castle Contractors

Lancashire (UK)

EMPEROL® Delivers a Factory Finish for Chemical Giant

our customers has been terrific and the green roof has been a real talking point.”

At a Glance:

Project: Richmond Park Golf Club Green RoofMaterials: KEMPEROL® V210 Waterproofing SystemContractor: Garhigh

Artists impression

The advanced chemistry of KEMPER SYSTEM’s innovative KEMPEROL® V210 cold liquid-applied waterproofing membrane will help ensure efficient manufacture of fluorochemicals and fluoropolymer materials thanks to a roof refurbishment project at AGC Chemicals in Lancashire.

AGC Chemicals is one of the world’s leading manufacturers of

fluorochemicals and fluoropolymer materials, and its production plant not only requires a dry environment on the inside but also needs a durable roof surface on the outside to accommodate regular footfall from maintenance staff.

The concrete slab roofs on two production site buildings at AGC Chemicals had asphalt surfaces that were widely failing with a potential risk

of leaking into the building below. This was evident by patches of blistering. Moreover, the seal around a number of redundant roof lights had also failed so AGC opted to refurbish the roofs as part of a general upgrade to the buildings and EMPEROL® V210, a cold liquid-applied waterproofing membrane from EMPER SYSTEM, was chosen as a solution that could be applied quickly with minimum remediation to provide a tough, flexible and long lasting surface.

Castle Contractors Ltd stripped away the existing loose material before making good the failed areas using EMPER SYSTEM’s ‘D’ Primer to prepare the surface; flooding the areas where the old substrate had been removed with special resins and graded fillers to create an even surface. The contractor then applied EMPER SYSTEM’s EMPEROL®

V210, a fleece reinforced resin based waterproofing system which cures to create a seamless, elastomeric, membrane that is durable enough to withstand regular footfall from maintenance teams and that also has an effective working life in excess of 25 years.

Comments Mark Atherton from Castle Contractors: “The original roof was in a poor state of repair and contained a wide range of roof details, including boxed off redundant roof lights and a brick parapet wall.

By using the EMPEROL® system, we were able to apply a new waterproof membrane with minimal preparation of the existing substrate and could seamlessly apply the new membrane

Walsall, West Midlands (UK)

EMPER Translates to Durable Solution at Secondary School A number of school roofs in the West Midlands now exceed building regulations for thermal performance thanks to the installation of a new STRATEX warm roof from KEMPER SYSTEM.

Barr Beacon School and language college in Walsall boasts several buildings on campus, each of which has existing insulation and a felt roof. Water ingress in some areas of the roofs led to a decision to refurbish and upgrade the roofs, comprising a combined area of around 900m2. Roofing contractor, Cooper Roofing, was brought in to carry out the work and specified EMPERTHERM insulation board from EMPER SYSTEM along with the roofing specialist’s EMPEROL® V210 cold liquid-applied waterproofing membrane.

Cooper Roofing carried out the programme in sections, completing each area of the roof before moving on to the next. Localised repairs were carried out to the existing roof and this was then cleaned and prepared for overlaying with the new STRATEX warm roof system. The existing roof membrane acted as the vapour control layer for the new roof and 123mm EMPERTHERM insulation was bonded directly onto the prepared substrate. This was then coated with EMPER SYSTEM’s D Primer and, once the primer had cured, Cooper Roofing applied the EMPEROL® V210 liquid waterproofing. The V210 resin saturates a flexible reinforcement fleece, which is laid in a single process and cures to create a strong, flexible and durable waterproof

At a Glance:

Project: 900m2 Roof Refurbishment STRATEX Warm Roof Materials: EMPERTEC D Primer; EMPEROL® V210

Waterproofing SystemContractor: Cooper Roofing

membrane that cannot delaminate.

Cooper Roofing completed the installation by stripping back the gutter areas where a new vapour barrier was installed, and creating a clean edge with a new GRP trim.

The STRATEX warm roof system from EMPER SYSTEM means that Barr Beacon have been able to renew the waterproofing integrity of the roofs and improve the thermal performance of the building in a single project, without the expense and upheaval of a major strip out.

Thanks to the 20-year warranty offered by EMPER SYSTEM the School can also be confident that the new roofing membrane will provide a long service life, maximising the value of the investment in the campus.

Photo courtesy of Eco Green Roofs

Millennium Seed Bank, Wakehurst (UK)

Seed-Based Resin eeps Rain Out at ew Seed BankKew Gardens’ Millennium Seed Bank can look forward to a drier future thanks to KEMPEROL® 2K-PUR, a cold liquid-applied waterproofing system from KEMPER SYSTEM made from….the seeds of the Ricinus Communis plant!

Opened in 2000 as a seed archive and research facility that stores millions of seeds gathered from rare and exotic species from around the world, the Millennium Seed Bank at Wakehurst

Place is a globally renowned facility. Ricinus Communis, more commonly known as the Castor oil plant is amongst the collections at ew and is a sustainable crop used as the basis for EMPER SYSTEM’s ground breaking solvent-free and odourless waterproofing membrane.

An accumulation of standing water in the distinctive sectioned roof’s back gutters had caused the welded joints to

degrade, resulting in leaks to the roof that had to be addressed.

Explains roofing contractor, Mark Draper from Draper Roofing: “The joints between the stainless steel rolled roof and the stainless steel lined gutters were designed to enable movement but, where the welded connection had begun to degrade, leaks had started to occur. In response to this, ew Gardens needed a solution that would be both

watertight and flexible and emper System’s range of cold liquid-applied membranes was the ideal answer.”

EMPER SYSTEM advised ew Gardens to select EMPEROL® 2-PUR for the project as the sustainably sourced and solvent-free resin and flexible reinforcement fleece, manufactured using a recycled plastic bottle content, delivered on ew’s environmental commitment. Moreover, as the solvent-free membrane is also odour free, it enabled the building to remain fully operational throughout the project, despite the close proximity of the air vents to the back gutters on the roof.

Draper Roofing primed the gutters with EMPERTEC® Primer before applying

the EMPEROL® 2-PUR resin. The resin saturates a polyester reinforcement fleece, which is immensely strong, flexible and tear resistant, and cures to form a seamless, homogenous membrane that cannot delaminate.

At a Glance:

Project: Kew Garden’s Millennium Seed BankMaterials: KEMPEROL® 2K-PUR Waterproofing SystemContractor: Draper Roofing

Photo © Helmut-altenleitner/Pixelio.de

THE DUC The Magazine for Liquid Waterproofing and Roofing Systems

Published by: emper System Ltd U Editing / Design: Stuart Hicks

emper System Ltdemper House30 ingsland GrangeWoolston, Warrington, Cheshire United ingdom WA1 4RW Phone 01925 445532 Fax 01925 57509

enquiries@kempersystem.co.ukwww.kempersystem.co.uk

THE DUCK Magazine for Liquid Waterproofing and Roofing Systems 76

Cambridge, MA (USA)

The MIT Dome, Massachusetts Institute of TechnologyIn 1916, Massachusetts Institute of Technology (MIT) relocated its campus from Boston to neighbouring Cambridge. After nearly 100 years of service, the waterproofing membrane under the famous dome began to reach the end of its service life.

As a result, water began to infiltrate the building and cause damage to the interiors and contents of the library located directly under the dome. The extent of the work would be great including staging the entire dome as well as removing and re-installing a majority of the existing limestone finish. Since fasteners were going to be installed through the new waterproofing membrane to secure the limestone, fluid applied waterproofing systems were considered as the penetrations could be tied in the seamless membrane. The construction process was going to take place during ongoing business hours. Therefore, minimization of disruption was also a consideration.

Solution: The limestone finish located on the lower third of the dome was removed and set aside for re-use. The red copper standing seam roof on the horizontal section of the stepped areas was sent to be recycled. The existing 4 ply hot asphalt waterproofing membrane was mechanically removed down to a clean, sound concrete substrate. After the removal and surface preparation, EMPERTEC® EP-Primer was applied to all surfaces and allowed to cure. Once the primer was cured, EMPEROL® 2-PUR resin system waterproofing membrane was installed onto all surfaces.

Planting the Seeds of a Successful Green Roof Specification

The historic fountain had been maintained with patch repairs over the years but the cost of topping it up, due to a variety of leaks, , was mounting for Preston City Council. The Council was keen to have the fountain repaired and operational in time for this summer’s

Preston Guild celebrations; an event that only happens once every 20 years and kicks off in August. The council awarded the contract to Castle Contractors Ltd, who had carried out a previous fountain waterproofing project in Chester, and the company was able to recommend

just the right product from the EMPER SYSTEM range.

EMPEROL® is cold liquid-applied resin which is used in combination with a non-woven reinforcement fleece to provide a durable, flexible waterproof membrane

Miller Park, Preston (UK)

Restored Fountain Makes A Splash At

Preston Guild Thanks To EMPEROL®

A listed fountain in Miller Park, Preston, has been restored to its former – watertight – glory in time for this summer’s Preston Guild celebrations thanks to the KEMPEROL® waterproofing system from KEMPER SYSTEM.

Lakeland, Florida (USA)

“Not many architectural designs actually capture your mind, your heart, and then your soul.”– Chuck Jablon, Skanska Building USA

At the new university in central Florida, the 120,000-square-foot Innovation, Science and Technology Building is the centrepiece of the campus master plan by visionary architect Santiago Calatrava.

The sloped glazing roof features 94 operable louvre arms that open and close to allow natural sunlight in. The first phase of the waterproofing application began in spring 2013. The building is scheduled for completion in 2014.

The drive towards more sustainable buildings has led to an evolution of green roofs from specialist eco-feature to much more mainstream specification. Whether the green roof is specified to help a building blend in to rural or semi-rural surroundings, to enhance biodiversity or to gain BREEAM points, it can be a striking addition to a building that matures to enhance the structure’s character over time.

However, the success or failure of a green roof depends on an effective specification that considers not only the structure itself but the location, orientation, shading and climate of the site. Only by working with waterproofing and green roof specialists that can offer a proven roofing system along with the required level of horticultural expertise can the specifier be confident of a viable long-term result.

Design Stage

While it may appear that planting can be decided at a later stage, in fact it is important that these decisions are considered at the design stage as the roof build-up impacts on the planting possibilities. For example, wildflower meadows are a popular choice for large expanses of roof surface, but they need plenty of moisture, which means designing the roof to accommodate the load and a greater depth of reservoir core and necessary growing medium required to keep the green roof healthy. Conversely, alpine planting needs much less water to thrive, which influences the load bearing capabilities required from the roof.

Green Roofs can also be incorporated in to a project as part of a SUDS design. Water stored to irrigate the green roof reduces the potential impact of new and existing developments with respect to surface water drainage discharges. Again, considering the planting at an early stage means that the specifier is in a much more informed position to understand the level of water that will need to be stored or released from the roof.

Watertight

The effectiveness of the waterproofing membrane used to create a watertight barrier between the roof substrate and the green roof system is the most critically important element of the specification. The membrane should be flexible enough to cope with any post build ‘settlement’, tough and durable enough to cope with the load bearing requirements of the planting medium and have a sufficiently long service life

to make the green roof viable.

A common green roof design would typically consist of an inverted warm roof build up, applying the waterproofing system to the roof substrate, followed by the insulation, and then the green roof elements. This can add an extra layer of protection for the waterproofing membrane as it is cushioned underneath the insulation. However, the use of EMPEROL® V210 or EMPEROL® 2-PUR with their

additional strength and flexibility, means that the waterproofing can be applied either below the insulation or above as in the case of a conventional warm roof. This is because these systems are FLL certified as root resistant so there is no risk of root damage to the integrity of the waterproofing membrane, even as plants mature and their root size increases.

Consulting the membrane supplier for technical support can help determine the right specification in this regard.

Location, Location, Location

In terms of specification of the green roof planting itself, client preferences and aesthetics have a role to play, but a key consideration should always be the location and prevailing climactic conditions as these govern the amount of light, heat, shade and moisture the roof will receive. The influence of surrounding buildings, which can also affect shading levels and exposure to winds also need to be taken into account. These factors should be assessed in combination to determine the viability of different types of planting.

Of course, no matter how carefully considered the planting specification, without proper maintenance post installation the green roof will not thrive. Establishing a maintenance plan and provision for the associated costs need to be factored in at the design stage for the aesthetics and benefits of the green roof to last long term.

Image courtesy of Santiago Calatrava and Festina Lente Services, Inc. Copyright 2012. All rights reserved

Chuck Jablon strongly recommended KEMPEROL® 2K-PUR to the architects for the special challenges of Florida Polytechnic University based on his previous experience working with KEMPER SYSTEM America. He also knew that the Atlanta-based Skanska team utilized the same system with proven success on the High Museum of Art project. The roof of the Atlanta museum includes hundreds of skylights.

Q. What were the primary challenges you faced on the waterproofing?

Two of the most important components on this project are the aesthetic value of the building skin and the functionality of the building envelope, as it includes many different components (glass, concrete and penetrations). Quite frankly, we were looking for a single quality product that would resolve our concern for waterproofing the many different components and would

complement the visual aesthetic of the project in the end.

All three roof surfaces have multiple components/penetrations to consider, including: electric, plumbing, HVAC, architectural / structural features, operating arms with hydraulic pistons, etc. In addition to these elements, waterproofing the skylights was a big issue, as the entire main roof deck is glass and concrete and all first-level classrooms are below a walkable concrete terrace deck that needed to be waterproofed. It was a huge concern that the waterproofing / roof system be impeccable, as leaks open the door to future risks.

Q. What about from a project management point of view?

Everything about this project requires special attention. All the trades are required to work on rotation, as the building is radial by design, and most of the detailed work must be done by hand. With the EMPER system, the applicator (TarHeel Corp.) was able to work in one area at a time, this allowed other trades to access adjacent areas and maintain schedule deadlines.

Among Florida Polytechnic’s 48 individual subcontractors are trades ranging from technology / security, HVAC, electric, sloped glazing, finish cabinetry and

concrete, working inside and out and in every area of the building. So it is very important for the management team to ensure that the product protecting the building from water is best suited for all project circumstances. Above all, the most important, the building cannot leak.

that bonds to almost any substrate and cannot delaminate. The EMPEROL® ‘BR’ product in the range was originally developed for bridges and car parks but its translucent beige finish made it the ideal choice as it blended superbly with the colour of the stone used to build the fountain.

Explains Neil Atherton from Castle Contractors Ltd: “The EMPEROL® V210 range is ideal for waterproofing

fountains as it can follow the exact contours of the fountain bowl with no joins. It is also U/V stable and has a service life of at least 25 years, ensuring a robust solution for a generation.

The standard EMPEROL® V210 finish is grey, which would have been very visible against the stone fountain, but by using EMPEROL® BR instead, we have effectively provided an ‘invisible’ waterproof membrane which maintains the character of this listed feature.”

Castle Contractors Ltd began by removing the existing failed coating and cleaning the fountain surface. The installation team then applied EMPER

SYSTEM’s EP primer before applying the EMPEROL® BR resin in a single process. The fleece reinforcement was cut on site to match the shape of the fountain’s ‘pond’ and central feature.

Applied in a single process, the resin saturates the fleece and cures to form a seamless waterproof membrane. The circumference of the 300m2 fountain pond was terminated into a chase to ensure that the waterproofing

membrane protects the structure to the very edge.

Completion of the project took just ten days and was accompanied by additional repair work and feature lighting, ensuring that the fountain is ready to take centre stage for the Preston Guild festivities.

8 www.kempersystem.co.uk

As universities adjust their business models in response to changes in funding structures, university campuses have seen a significant investment to address the increasingly competitive nature of the higher education sector. Continuing pressures on finances in the sector mean that development projects must focus on durability that will deliver value and sustainability on a ‘whole life’ basis. However, a university campus must also sell itself as an attractive place to live and work so there is also a clear aesthetic imperative to enhance the built environment with schemes that are attractive as well as being energy efficient and practical.

At Huddersfield University, recent improvements to facilities include four new buildings, including a new sports hall, Dean’s office and corporate suite, designed by architects Watson Batty. The four buildings have been constructed with a single steel frame and all adjoin each other but rise to different heights varying from 2-4 storeys. To enhance the biodiversity and aesthetics of the development, green roofs were specified for three sections of the building, including the sports hall, and a warm roof was specified for the corporate suite. The variation in height of the inter-connecting roofs means that some roof areas overlook the roofs of others, and the fact that the lower roofs are mostly shaded presented challenges in terms of both planting and drainage. Addressing those challenges became a team effort between the architects, the roofing contractor, Cawston Roofing, the green roof supplier ABG and the waterproofing specialist, emper System.

Holistic Specification

While the intention for the buildings had always been to install a combination of green roofs on three of the four roof areas and a traditional warm roof build-up on the fourth, the architect had originally specified a single ply membrane as the waterproofing system for the project. However, having used the EMPEROL® V210 cold liquid-applied waterproofing membrane from EMPER SYSTEM for around 30 years, Cawston Roofing suggested to the architect that this would offer a more practical and durable alternative for a similar installed cost as the original

specification. Meanwhile, ABG had developed an innovative ‘blue roof’ drainage system, which puts a high density polyethylene (HDP) reservoir under the growing medium to replace the more conventional SUDS system, reducing the installation time and avoiding costly and time-consuming excavation of separate drainage tanks.

Explains Nick O’Mara from Cawston Roofing: “The Huddersfield University project demonstrates how important it is to consider specification decisions in a holistic sense rather than thinking about material costs in isolation. For the green roof system, avoiding the need for a SUDS system saved time, money and costs on site. For the waterproofing membrane, a change to EMPEROL® V210 meant that we could be more flexible with the programme and more creative with the roof build up as well as providing an FLL certified root-resistant and robust waterproofing membrane with a guaranteed service life.”

Innovative Approach

The proposal from Cawston Roofing and ABG was to invert the roof by applying the EMPEROL® V210 waterproofing membrane first, followed by the insulation, the blue roof drainage reservoir and then the growing medium.

“Applying the waterproofing membrane first provided a key advantage on site”, explains Nick. “It meant that the roof of the building was completely water-tight earlier in the installation process, saving valuable construction time; allowing fit out works on the lower levels of the building to take place sooner.”

For the three green roofs, Cawston Roofing applied EMPER SYSTEM’s EMPERTEC EP primer direct to the concrete slab substrate and, once this had cured, the EMPEROL® V210 cold liquid resin was applied. The EMPEROL® V210 resin saturates a non-woven reinforcement fleece and cures to provide a seamless, monolithic membrane that is tough and permanently flexible. Finally, Cawston Roofing installed 180mm insulation board onto the cured waterproofing system, followed by a slim line breather membrane, before passing the installation to ABG to complete the green roof element of the project.

ABG installed a 40mm deep ‘Blue Roof’ drainage reservoir onto each of the three green roofs which provides collection and storage or rainwater to irrigate planting during dry periods, and offers a continuous drainage layer across the roof structure with attenuation capabilities which helps control the discharge of storm water. The growing medium and planting was then individually selected for each roof to take account of the roof area, location and level of shade created by surrounding buildings, with biodiversity measures built in to the specification.

Explains Martin Lambley from ABG: “The sports hall roof has been designed as a

wild flower meadow with planting of native species and areas of biodiversity, including log and rock insect nesting boxes and sandy and shingle areas. The other two roofs are at a lower level and are shaded by areas of the new building and adjacent existing buildings so here we used drought tolerant sedums and alpine planting.”

Multiple Benefits

The corporate suite section of the building has a metal deck roof and here the roof build up featured a vapour control layer installed directly onto the substrate followed by EMPERTHERM warm roof insulation. Cawston Roofing

prepared the insulated substrate with EMPER SYSTEM’s EMPERTEC D primer and, once this had cured, applied EMPER SYSTEM’s EMPEROL® V210 waterproofing membrane with the same wet-on-wet process used for the green roofs.

Nick adds: “Throughout the roofing process, switching to a cold liquid-applied waterproofing membrane enabled a much more flexible programme which speeded up the installation. Because the emperol waterproofing system bonds seamlessly to any substrate, including verticals, waterproofing of details on the roofs, such as pipe penetrations and drainage outlets was also made quicker and easier, as was the application of the waterproofing system on the upstands. This project really demonstrates how beneficial it can be to consider buildability benefits as well as functionality when specifying a roofing system.”

At a Glance:

Project: Huddersfield UniversityMaterials: KEMPERTEC EP Primer KEMPEROL® V210 Waterproofing SystemContractor: Cawston Roofing

Huddersfield (UK)

Real Value and Buildability Raise the Roofing Standards at Huddersfield University