Frequently asked Questions.

  1. What is Hertalen EPDM?
  2. When was EPDM invented?
  3. What Colour is Hertalan EPDM?
  4. Where can it be used?
  5. Can I walk on it?
  6. My flat roof extension is very cold what can I do about it?
  7. Is your insulation Environmentally friendly?
  8. Is Hertalan EPDM Environmentally Friendly?
  9. Can a green roof help me get planning permission?
  10. What is the difference between an extensive and an intensive Green Roof?
  11. Does having a Green Roof Affect my Warranty?
  12. How much does having a Hertalan EPDM roof cost?

What is Hertalen EPDM?

Hertalan EPDM or Ethylene Propylene Diene Membrane is an Environmentally friendly synthetic rubber that has some remarkable qualities that has been specifically designed for use on flat roofs.
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When was EPDM invented?

At the end of the 1950's, the product EPDM was invented initially especially for the Middle East. The Middle East climate requires a product that is resistant against large temperature fluctuations. Moreover the product has to be fully flexible and capable of withstanding temperatures between -70 and +120 °C, EPDM proved to be this product. The advantages of this type of roof covering speak volumes. In 1960 The Dutch State Mines DSM and Hertalan Rubber Products (formerly Hertel Rubber Products) became the first producers of EPDM in Europe with the production of Hertalan EPDM roof covering. Hertalans oldest roof is over 40 years old and showing no signs of fatigue!
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What Colour is Hertalan EPDM?

Our EPDM is carbon black in colour.
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Where can it be used?

EPDM can be used on almost all flat roofs large or small. Because of its root resistant qualities it can also be used for an Environmentally friendly Green Roof
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Can I walk on it?

Yes you can as Hertalan EPDM is very tough and for domestic use is 1.2mm thick! However if you foresee heavy pedestrian traffic it is best to fit our recycled eco friendly tiles. These are made from recycled off cuts at the factory and come in several colours. They can provide you with a defined pathway on your roof and more importantly protect the EPDM from any sharps that might accidently be walked onto the roof through heavy traffic use.
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My flat roof extension is very cold what can I do about it?

Most older flat roofs have been built with a cold roof construction (insulation under the roof deck and above the ceiling) which is not inherently as efficient as a warm roof (insulation on the roof deck surface) or may not have any insulation at all! At Sussex Green Roofs we can assess the structure of you roof and advise on the best means to increase your insulation. Building regulations require an increase in insulation to current standards (u value of 0.25 for flat roofs) when ever work is carried out and advise that warm roof is the best solution. The Insulation boards are fixed to the surface after correct preparation and then the Hertalan EPDM is bonded to it to form a very light weight but highly insulating waterproof solution.
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Is your insulation Environmentally friendly?

Yes! We use Celotex PIR insulation boards which have zero ozone depletion potential and have recently been independently assessed by the Building Research Establishment with full “cradle to grave” profile taking into account the full lifetime environmental impact, including raw material extraction, manufacture, distribution, in-use performance and disposal. Celotex offers the most sustainable insulation, with the products achieving the lowest environmental score and lowest carbon footprint! Celotex is proven to be the most sustainable PIR insulation. This really does make your flat roof a Green Roof!
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Is Hertalan EPDM Environmentally Friendly?

Because Hertalan EPDM has a life expectancy of well over 50 years and thanks to this extended life span, its easy ability to be recycled and its low impact on the environment it carries the backing of Greenpeace as being the most sustainable product available for flat roofs! It is also manufactured to very high environmental management standards ISO 14001 and 9001. Its is also recommended both by the Government and the International Kyoto Ecology agreement that EPDM rubber is the Best Value sustainable eco-sound roofing meaning that you can be assured that your Sussex Green Roof is an Environmentally Friendly Roof. You can one step further and add a Green Roof too!
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Can a green roof help me get planning permission?

Green roofs improve the aesthetics of a building, especially when the plants flower, with small blooms of yellow, pink, white and red flowers appearing at different times of the year.  These aesthetic qualities also help dramatically when applying for planning permission for new buildings as, not only does the green roof actively remove pollutants from the new site, it may be used to disguise or even hide the new development.
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What is the difference between an extensive and an intensive Green Roof?

An Intensive Green Roof could be thought of as a Garden on a roof with lots of shrubs, flowers even trees along with walkways and flowerbeds. At Sussex Green Roofs we would only really suggest this kind of Green Roof on a new build home designed specifically for this or on a commercial building due to the size and strength requirements of the structure
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An Extensive Green Roof is much simpler, is low maintenance, much cheaper but can bring the same aesthetic qualities bringing colour and natural habitat to an urban environment. We use Hertalan EPDM as the waterproofing membrane which is totally root resistant. Over this is laid a protective moisture matt which sits below a drainage and water retention board, another layer of moisture matt and then the growing medium/substrate. There are then several options: The quickest is to lay a sedum blanket which already has a collection of plants, ferns, mosses and small flowers. The second is to plug plant, this enables us to choose exactly which plants you want on you green roof and to tailor colours and so on. The last is to spread sedum which will take a little longer to establish but give a similar look to the other options very quickly.
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Does having a Green Roof Affect my Warranty?

No, Not at all! Your Hertalan EPDM fitted by Sussex Green Roofs comes with a 20 YEAR MANUFACTURERS GUARANTEE regardless of whether you fit a Green Roof to it. It is the incredible qualities of the EPDM that allow the Green Roof to be fitted and it can even extend the life of your flat roof by providing further protection from the elements. Remember, Hertalan EPDM is certified to German FLL standards for root penetration. It can even withstand Bamboo!
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How much does having a Hertalan EPDM roof cost?

Compared to a high performance 3 ply felt roof professionally fitted with a 7-9 year guarantee our EPDM does not cost significantly more. Remember thought that a Hertalan EPDM roof fitted by Sussex Green Roofs comes with a 20 YEAR MANUFACTURERS GUARANTEE has a life expectancy over 50 years! No felt roof even comes close to these numbers! Over the life of your structure you could save a huge amount of money, time and aggravation by not needing to replace your felt several times and the inconvenience of it failing unexpectedly! We encourage you to find out about the costs and the difference in quality of the different products as we are sure you will decide on a Hertalan EPDM roof fitted by Sussex Green Roofs.
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