As any self-respecting EPDM installer will tell you, single-ply can be a smart, durable and cost-effective long-term flat roofing solution – but only if you treat it like the skilled craft that it is, and respect the rubber. 

On the surface, it might not look like much – huge black roll, cold to the touch, about as exciting as an overgrown yoga mat, right?

Wrong.

Diary of an Earnest EPDM Fitter

by Rufus Well

Entry One – Respect the Rubber

Never underestimate this waterproofing warrior. Laying EPDM isn’t a slap-it-down-and-hope-for-the-best scenario, it’s precision craftsmanship. A symphony of timing, temperature and tension, the very success of which depends on a confetti of variables.

Those who get it, get it. Those who don’t, soon will.

Take me, for example, a stalwart felt fitter by trade. In the late 80s, I reluctantly rode the wave of the EPDM revolution, retraining as full-system fitter of a product not only superior in quality, durability and aesthetics, but also a flat-out gamechanger for the earnest flat roofer.

Soon, wherever I looked, felt had fizzled out and rubber ruled as the resounding residential roof choice countrywide. Seizing change as opportunity, I upskilled, and pretty soon was on a roll, leading a small, dedicated fitting team keen to embrace a pivotal industry advance.

Still going strong after thirty years

At the top of our road, still going strong thirty years on, sits my first ever RubberCover roof, a modest porch and my badge of honour. Next door, a massive newbuild extension, same product, same purpose, same promise. Providing of course, that the job’s done right.

Now, I’m no cook, but when it comes to EPDM, I know my onions.

Over the years, I’ve perfected my method, my product choice and my finishing touches by never taking the fitting day weather for granted and always being prepared for worst case scenario.

Think of EPDM like wallpapering your lounge, except you’re 15 feet up, the paper weighs 70kg and the sun’s hotter than the Sahara, meaning the water-based glue you planned to use is now a no-no.

The heat is on. One bad choice could be a leak in six months’ time.

So, you switch to sun-smart bonding adhesive, cooly move the membrane out of direct sunlight to prevent thermal expansion, and shout down to the homeowner that, ‘yes please, a cuppa would be champion’ while you monitor the clouds and decide if that storm on the horizon’s going to be a problem.

Unrivalled protection

Correctly installed, EPDM is a thing of beauty and durability.

Wind, rain, sleet, snow, nothing is getting through. It shrugs off UV rays like a forcefield, resists shrinking and cracking, and can last for over 50 years with barely a whisper of maintenance.

But getting to the point of unrivalled protection takes respect for the process and a willingness to learn.

My top tips for trainee EPDM fitters

As a veteran flat roofer with hundreds of thousands of square metres under my belt, I’m often asked my five top tips for trainee fitters.

These would be:

1. Sound foundation prep. Your surface has to be spotless. Grease, dust, leaves – they’ve all got to go, pronto. You don’t want a call back in three months’ time only to find that a rogue tack under your rubber is now a major leak in angry Mrs Smith’s kitchen extension. Prevention is much better than cure, and a lot less costly.
2. Be weather-wise and adhesive-savvy:
   • Extreme cold: Beat the freeze, switch water-based adhesive for bonding adhesive if temperatures fall below 5°C, or it’s expected to dip below 5°C in the 48 hours after fit.
   • Excessive heat: In temperatures above 23°C, water-based adhesive can quick-dry, causing weak bond or bubbles. Switch to bonding adhesive instead, applying to both membrane and deck for strong adhesion.
   • Wind: No one wants to see an EPDM kite flapping down the street. If necessary, ballast the membrane temporarily to avoid lifting or lift-off.
   • Humidity: Condensation is a flat roofer’s kryptonite. It threatens moisture problems inside your roof build-up, even if the membrane itself is watertight. If it appears on the rubber, stop fitting immediately and await better conditions.
   • Keep an eye on tack off: Laying EPDM before your bonding adhesive has gassed off can trap solvents, causing bubbles and blisters. Fit too late and your rubber won’t stick at all. Push a finger into the glue, poke and lift. If it’s stringy, it’s not ready.
3. Perfect the ‘fiddly’ bits: Corners, edges, penetrations – mastering these techniques is an art to take pride in. I’ve always said, ‘Get it right, you’ll be watertight. Get it wrong, and it won’t be long … before it rains on your parade’.
4. Show patience. A patience that says ‘I’ll wait another 10 minutes for my adhesive to fully tack off for absolute confidence in this install.’ Even when the clouds are gathering, the clock’s ticking and you’ve got a hot date – wait.
5. Get it right first time: EPDM doesn’t forgive shortcuts or sloppy workmanship, but if you take your time, plan your moves and roll with care, it’ll reward you with a robust roof that quietly gets on with the job, year after year.

Watch this space for more tales of the unexpected from up on the roof.

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