Well here’s a question we get asked quite frequently.

In frankness, it’s all in personal perception and the project you are envisaging.

Both systems have first-class waterproofing qualities.

So in a line, the answer is yes and no – depends on circumstance really. Each system has its fans.

Who’s to say which is best?

Roofing Kits Direct provide both systems and so we are not biased. Below are appraisals of the two systems where we have tried not to be influenced by personal opinion nor rumour.

Remember your building or roofing contractor may have a preference – if so they are likely to do a better job using materials they are familiar with.

Life expectancy and Longevity.

Very good for both products, 25 – 30 years for fibreglass and up to 50 years for rubber. Rubber is more susceptible to accidental sharps damage and vandalism however both are easily repairable for isolated minor damages.


Fibreglass – NHBC approved, Fire retardant

EPDM – BBA approved – NHBC approved – Fire rated


Fibreglass costs a little more than EPDM, both are more cost-effective in the long term than Felt. Fibreglass is better suited for foot traffic elements such as balconies and elevated decks. However, Rubber can be easily over paved using geotextile fleece and paving slab supports.



  • Green roofs
  • Lightweight
  • Visually attractive
  • Colour options
  • Strong
  • Jointless under 50 sq.m
  • Complex shape compatible
  • Large roofs require expansion joints
  • No hot flame required.


  • Green roofs
  • Lightweight
  • Flexible
  • Strong
  • Complex shape requires joins
  • Suits uniformly shaped roofs
  • No hot flame required.
  • Visually standard

Damage resistance

Fibreglass has a very high resistance factor even to vandalism – EPDM is very durable but may have issues with sharps and vandalism.

Repair Profile

Both are very easily repaired, done well a fibreglass repair is almost invisible. Rubber repair has higher visibility.


Fibreglass is first class and easily cleaned and at RKD comes in Light and Dark Grey. The rubber is black, as you would expect and has a good clean appearance. Also, rubber is easily cleaned.

Both systems use edge trims to provide clean and professional-looking finishes.

So let’s look at the pro’s and cons



  • Visually
  • Complexity compatible
  • Foot traffic compatible
  • No joins
  • Resistant to sharps
  • Good repairability profile
  • Not hot flames required
  • Good Longevity
  • Small roofs good for DIY


  • More expensive than EPDM
  • Mandatory to be dry throughout installation
  • Mixing ratios to be considered
  • Large roofs require expansion joints



  • Cost effective
  • Easy to install
  • One piece
  • Can be joined
  • Good repairability profile
  • Not hot flames required
  • Great longevity
  • Good for DIY


  • Complexity means joins
  • Requires additionals for foot traffic
  • Needs to be dry
  • Potential shrikage
  • Susceptible to sharps

Roofing Kits Direct believe both systems are very high quality and value for money, which is why we sell them. They can be installed easily by a competent DIYer when the roof is of small-med size. If the roof is straightforward EPDM installation is a little quicker.

RKD would express a preference for both these systems as opposed to felt – but then we would; wouldn’t we.