Before sustainability became a popular concept in building
design, ballasted EPDM roof systems were widely used. Dating to the
1960s, this time-tested, reliable roof system still offers more
sustainable features than many systems currently available.
A ballasted EPDM roof system has its components held in place by
river-washed stones or pavers. Ballasted roofs are loose-laid,
meaning roofing materials, including the insulation and roof
membrane, are not fastened to one another or to the roof deck.
Adjoining EPDM sheets are spliced together, and the membrane and
insulation are held down with a minimum of 10 pounds of ballast per
square foot. This system has been popular because of its low life
cycle cost and quick, economical installation, which is one of the
fastest and most cost-effective ways to achieve a weatherproof
building envelope. When the system first was introduced,
45-mil-thick EPDM was common. More recently, there has been a trend
to using more puncture-resistant 60-mil- and 90-mil-thick EPDM
Log in or register for FREE access to this article and other Professional Roofing online content.