A Beginner's Guide to EPDM Roofing Systems

If you have a flat roof which is in need of repair, or are thinking about a new one, you may be aware of EPDM (ethylene propylene diene monomer (M-class) rubber). This rubber roofing sheet is manufactured from ethylene, propylene and diene, the ‘M’ denotes monomer, the grade of rubber which the material comes under in the American Society for Testing and Materials (ASTM) classification codes. This unique rubber roofing material contains elements which are essential to providing an effective protective barrier in roofing materials.

An EPDM that has been proven for over 50 years

EPDM has been proven over 50 years to be one of the most effective types of roofing protection. It is efficient, cost effective and lasts for many years. One important benefit of the rubber membrane is that it does not require any heat or flames during installation which means that it is safer for the installer and the property owner.

Larger membrane sizes to minimise the number of joins

The larger membrane sizes which are a feature of EPDM membranes means that you do not experience the amount of joins that are a factor in traditional felt roofing systems. This prevents the possibility of leaks or weaknesses appearing in the roofing membrane where traditionally the overlapped seams would become brittle with age and become the first weak point which allows water penetration. With EPDM roofing membranes where joints do occur, these are not considered a weak point with the system as they expand and contract at the same rate as the membrane and are in fact tested and proven to be as strong as the membrane itself.

Fleecebacked EPDM for superior strength

RubberBond membranes have further simplified and strengthened the jointing method of their fleece backed EPDM membranes by using Factory Applied seam Tapes (FAT™), this is where the membranes have a seaming tape bonded to the membrane in factory conditions making it stronger, better and faster to install than other EPDM jointing systems and traditional flat roof seaming methods.

• Why use EPDM for Roofing?

  A major reason that roofing professionals will use RubberBond FleeceBack EPDM over other roofing materials is the ease of installation, quality of materials compared to others on the market and it’s what property owners are asking for.

  Over the last 10 years in the UK, EPDM roofing systems have dramatically risen in popularity; this is due to a number of factors but primarily property owners demand for a long term solution to their flat roofs.

  With this popularity, there has been confusion over whether EPDM membranes are the same. Sales jargon makes it very difficult for property owners to decide what is best and who to employ to carry out their roofing work. The membranes range from basic thin DIY membranes to professional trained installations of reinforced EPDM.

  Basic EPDM membranes for the DIY installer

  Basic EPDM membranes that are available to anyone from online shops or auction websites are popular for the DIY installer and the occasional roofer as they are cheap and from a picture of a roof it is hard to initially tell the difference in quality. These cheaper types of EPDM are often only 1mm thick and have only been around since the early 1980's.

  

  RubberBond FleeceBack EPDM is a total of 2.54mm thick, 1.14mm of this is EPDM, that layer alone is 14% thicker than what a lot of home owners are offered. The EPDM used in RubberBond FleeceBack is manufactured by Carlisle SynTec who have been manufacturing EPDM roofing systems since the early 1960's, the only EPDM manufacturer who can honestly say that their EPDM can last for over 50 years.

  Now you may be saying, "Great! RubberBond EPDM is thicker, but what about the FleeceBack? What does it do for me?" RubberBond FleeceBack has a thick polyester fleece laminated to the underside. This is for more than just showing you an impressive product sample. Standard EPDM membranes are proven to shrink, in some cases up to 10%, this should be controlled by mechanically tying the membrane into the roof surface by a fixing plate or strip around the perimeter often called a peel stop or base tie in which can be expensive and not always installed. FleeceBack EPDM does not require this base tie in feature as fleece reinforced epdm does not shrink. Once installed it stays where the installer meant it to.

  Fleece reinforcement for extra strength

  Fleece reinforcement also adds strength making it 180% greater tear and 60% greater puncture resistance than even the thicker 1.52mm EPDM membranes that are used in industrial roofing. The strength doesn’t just stop with the membrane - the fleece backing improves the bond strength to the roof surface, giving an extremely high bond to a range of surfaces whether it is an overlay of the existing surface or a new build.

  The most important part of any roofing system is the installer. RubberBond FleeceBack EPDM roofing systems are only available and used by approved and trained installers meaning that you won’t find it in a DIY store, builders merchant or be able to buy it online. Training and approval is an on-going process with yearly inspections of work. This helps to ensure that approved contractors only offer the best services. Not all other EPDM suppliers or installers can offer the same.

  Safe EPDM membrane installation

  Most people will have had a flat roof covered at some stage in its life. The traditional built up bitumen process created a strong odour and a potentially dangerous heating process as a hot flame was used to heat the material to bond the layers together and seal the joints. This provided a good seal, but the material is susceptible to cracking over time due to expansion and contraction. EPDM rubber roofing, however, is completely safe to install and has the flexibility to expand and shrink back with the seasons and their associated weather conditions.

  

  The roof does not require a covering with stones, gravel etc. like traditional felts but is a perfect substrate for using the roof as a green roof or terrace.

  EPDM is completely weatherproof, and can easily cope with extreme low temperatures down to minus 50 degrees Celsius and up to 150 degrees Celsius. It is flexible enough to cut and fit round any contour or awkward area.

• Types of Roofing Systems

  Popular roofing systems are listed below. Please click on the relevant link to find out more about the specific system and it's performance vs. RubberBond EPDM.

  • Modified Bitumen Roofing
  • TPO Roofing
  • EPDM Roofing
  • PVC Roofing
  • GRP Roofing
• Benefits of RubberBond FleeceBack EPDM Rubber membranes

  RubberBond EPDM roofing membranes are high quality, durable, energy efficient and weather resistant. Perfect as a roofing material for flat roofs or low sloping roofs and this is why they are well known as the perfect roofing solution and are very popular in the UK. The rubber material acts as protection against a variety of weather conditions including rain, hail, strong sun, frost and snow. The fleece backed membrane is more resilient to tearing and impact than other comparable roofing materials. Carlisle SynTec EPDM roofing membranes have been proven to enjoy a life expectancy of 50 years or more.

  

  Long Lasting and Durable

  Durability is a very important quality of roofing membranes. Types of roofing membranes that are weak and are not durable can easily become damaged, weakened by the weather or debris. EPDM is a highly durable rubber material that is used worldwide as protection on flat roofs.

  Resistance to Outside Elements and Weather

  One important quality of the fleece backed rubber membrane material is that it is unaffected by extreme of temperature, being highly resistant to snow or frost and is also resilient to continued UV rays and hot sun.

  Benefits of Installing RubberBond FleeceBack EPDM

  • The superior strength of the 2.54mm fleece reinforced EPDM
  • No shrinkage – unlike standard EPDM membranes
  • No creases unlike standard EPDM membranes
  • Faster, stronger adhesion to all surfaces with the fleece backing
  • FleeceBack adds toughness, durability and ease of fitting
  • 180% greater tear and 60% greater puncture resistance than 1.52mm EPDM
  • Better coverage of existing surface unlike thinner EPDM membranes
  • Only available to approved contractors, not to the DIY sector
  • No installation of peel stops or base tie-ins necessary

  RubberBond FleeceBack EPDM Quality and Performance

  • The fastest, most reliable and best looking system to install
  • Proven to last for over 50 years
  • 20 year insurance backed guarantee scheme
  • No heat or welding during installation
  • Clean & safe to install
  • 67% fewer seams than modified bitumen roofs
  • Greater puncture resistance than most modified bitumen roofs
  • Will not tear, split or crack
  • Able to be easily fitted at any time of year

  EPDM is suitable for all roof surfaces and uses both on:

  Domestic Roofs - extensions, garages, dormer roofs, green roofs, balconies, warm cold & inverted roof design, apartment blocks, orangeries and houses.

  Refurbishment of old flat roofs - Overlayment of existing surfaces such as smooth BUR, mineral felt, liquid asphalt, GRP or direct to existing roof substrate.

  Industrial Roofs - Office roofs, warehouses, gutter linings, bin stores, green roofs, sports centres and hospitals.

  New Build projects – Flats, apartments, houses, schools, offices and domestic projects.

• EPDM Manufacturing Method

  EPDM roofing membrane is manufactured in sheets made up of oils, zinc oxide, carbon black, curing agents, and polymers to increase membrane elasticity, strength, and durability. The membranes are formed into large sheets and placed into a type of oven that cures or sets the membrane to become the solid sheet that is used for roofing. For RubberBond FleeceBack membranes the thick fleece layer is laminated to the underside of the EPDM membrane by a patented method where the fleece and EPDM are under the same tension and put through a priming and heating process to weld the two materials together to form the strong, thick EPDM membrane with fleece backing.

  The manufacturing of the sheet goes through one more process of applying Factory Applied Tape, an uncured tape, to one side of the roll to give the installers and the property owner a stronger, faster seam on their flat roof where half the process has already been done in factory conditions ensuring exact placement and precision.

• EPDM Application Method

  RubberBond FleeceBack EPDM is available in two sizes of rolls, 3.05m and 1.52m wide. Standard EPDM is available in wider rolls than the FleeceBack version but due to the increased weight, thickness and manufacturing precision of the FleeceBack EPDM, 3.05m is the optimum size for manufacturing, handling and roof installation.

  FleeceBack EPDM can be fully adhered, mechanically fastened, or ballasted, but fully adhered is the standard method as this gives the best visual end results whilst still being cost effective. The system is fully bonded to the roof substrate and upstand details with a range of unique adhesives specifically developed to be used with EPDM and roofing applications, roofing adhesives need to be manufactured and tested to withstand all the temperature changes and extremes across a 90°C difference that roofs can encounter.

  The original method of jointing EPDM membranes used to be carried out using a type of liquid adhesive that joined the sheets together, this then evolved into using uncured EPDM seam tapes in conjunction with primer that are positioned between the two overlapping sheets by the roofer to vulcanise the EPDM membranes together. RubberBond FleeceBack EPDM has taken this process one stage further by applying the seam tape to the side lap of the roll during the manufacture process to ensure exact placement and strength of the 75mm wide tape, is called Factory Applied Tape (FAT™), making installations easier, faster and seams completely reliable.

  Joining the ends of the FleeceBack rolls together needs to be done by butt jointing and overlaying the butt joint with a 150mm wide cover strip. We use cover strip in these areas as you cannot install an overlap seam where the fleece underside overlaps onto the rubber. This is why you will occasionally see this alternate type of seaming method.

  All other corners, roof details and pipes are made water tight with either a pre formed detail such as a PS pipe boot or by using 225mm Uncured Elastoform Flashing tape. This tape is always used in conjunction with RubberBond EPDM Primer to seal the roofing membrane to virtually all surfaces. The tape is mouldable and stretchable to form it into any shape and detail required. Once placed onto the primer this forms an instant and permanent watertight seal.

RubberBond FleeceBack EPDM is solely imported and distributed by Flex-R Ltd throughout the British Isles. Flex-R train all installers of the RubberBond FleeceBack EPDM system ensuring they have the knowledge and skills to be able to install your flat roof to the highest standards required to become an authorised RubberBond installer. Click here to find your local approved installer.