Help with Age of EPDM

I’m trying to determine the production date of this epdm. Is it encoded here? Sorry if this has been covered already, but I can’t find info on deciphering this. I get the 60 mils, etc.

12402FRAF 060 EPDMFR 18:52



Well I’ll go out on a limb here.

My shot is the 124th day of 2002. It is the 60 ml variety rather than the 45 ml

Not set in stone though. Happy to be corrected

As good a guess as any. FR might mean Fire Rated.

Never heard of them having a date code but that tiny section photo does not tell the story. .

Un update. Just had a new roof using the exact same format as above but started with 41019, not 12402.
So that shoots down the 124th day scenario, but the 19 is the year, so whatever the 124 or 410 mean is up for grabs, but the 4th and 5th numbers are highly likely the year

Maybe the first three (or sometimes four) numbers are the month and day :thinking:

Is the age critical to something, or is it just fluff for your report?

Why don’t you call the Mfg if it is?
Live tech support on line works great. Eliminates wild ass guesses.

                               Evaluation of EPDM Age

Seam Technology History

  1. From the early 1960s until the mid-1980s seams were using white gas (cleaning) and a Neoprene-based splicing adhesive. The Neoprene polymer in the splice cement would sometimes break down and lose strength with prolonged exposure to ponded water.

  2. In the mid-1980s, a butyl-based splice adhesive was developed that was very tolerant of ponded water, but the seaming process was complicated, leaving seams prone to problems caused by workmanship.

  3. By the early 2000s, customized primers and double-sided seam tape emerged. These products dramatically simplified the seaming process and reduced workmanship inconsistencies.

  4. Around 2005 EPDM became available with primer and tape factory-applied to one edge of sheets. This innovation reduced warranty claims by nearly 80%.

Improvements to Angle Transitions (flat roof to parapet wall)

Early in its history, wood nailing strips were used to secure ballasted EPDM where it up-turned at the base of parapet walls. As EPDM membranes experienced age-related shrinkage, wood strips experienced pull-through. In the late 1980s, a new method emerged. Reinforced membrane attachment strips were attached to the roof with fasteners and a seam plate combined with adhesives improved this condition.

Puncture Resistance

Early in its history, 45-mil non-reinforced EPDM was common, especially in ballasted systems common on commercial buildings.

In the mid-1980s, manufacturers began producing a 60-mil EPDM with an internal scrim, increasing puncture resistance by about 50%. The problem with an internally-reinforced membrane is that it contains less weathering material over the scrim. On 60-mil sheets of EPDM, the thickness of the weathering material was only 20-25 mils.

In 1996, an externally reinforced, fleece-backed EPDM with a full 60 mils of weathering material was introduced that increased puncture resistance by about 300%.

Flashing Improvements

From 1962 to the mid-1980s, wall and penetration flashings were manufactured from uncured Neoprene. This material formed and spliced very well, but its UV resistance was poor. Over time, Neoprene flashing would crack and craze, and it became one of the most common courses of failure.

Flashing made of uncured EPDM was introduced in the mid-1980s. Uncured EPDM flashing offered dramatically improved weathering properties and none of the cracking issues.

Prefabricated pressure-sensitive inside/outside corners, pipe boots, and pourable sealer pockets for EPDM systems were developed and quickly gained popularity because they simplified the application process and improved quality.

Modern, pressure- sensitive flashings provide a full 60-mil EPDM weathering layer laminated to 30-mil cured adhesive for a 90-mil total thickness. This is a significant improvement over older methods.


Nice article of EPDM evolution Kenton.