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Ballasted System

Firestone EPDM Ballasted System


The Firestone EPDM Ballasted System is an economical EPDM Roofing System, suitable for a wide variety of buildings. It can be applied on any building that can accommodate the extra load of the ballast and where the roof slope does not exceed 10%.


  • Low installation cost
  • Use of large EPDM sheets
  • Fewer seams
  • Fast installation
  • Large choice of compatible substrates
  • Excellent fire rating
  • Superb weathering resistance


EPDM sheets are loose laid over an acceptable substrate. Adjoining sheets are overlapped a minimum of 100 mm and the seams are spliced with Firestone QuickSeam Splice Tape. Roof perimeters and penetrations are flashed in accordance with Firestone specifications (PDF). Once completed, the EPDM membrane is held in place using one of the following materials as ballast (with a minimum weight of 50 kg/m²):

  • Gravel in form of round, smooth, river washed aggregate without broken pieces (nominal 16 to 32 mm).
  • Concrete pavers with smooth trowel finish (min. 50 mm thickness).
  • Crushed gravel that must be graduated.
  • Poured in-situ concrete.

Prior to selection of this system, the specifier should evaluate structural conditions of the building to verify its load bearing capacity. Roof slopes and wind requirements should also be investigated.