Cush-A-Block, Rooftop Block Support

ZSI-Foster has designed rooftop support systems that utilize 100% recycled rubber that qualifies for LEED credits and meets the Buy America Act. The units are resistant to extreme temperatures and can withstand the year-long sun and hot temperatures Hawaii has. The rubber also helps with dampening the sound and vibration that equipment can generate. Combining the Cush-A-Block with Unistrut channel, rollers, raised channel and crossbeams gives technicians a complete line of options to support your HVAC, plumbing or electrical equipment needs.

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Catalog / Product Literature: 

Cush-A-Block, a rooftop support block, provides a support for gas piping systems, electrical conduit, HVAC equipment, and other applications such as:

  • Solar Racking
  • Pipe & Conduit supports
  • Duct supports
  • HVAC supports
  • Cable Tray Systems
  • Air Conditioning supports
  • Roof Walkway supports


  • 100% recycled rubber
  • LEED Certifiable
  • Meets the Buy America Act
  • American Reinvestment Recovery Act (ARRA)
  • independent Laboratory Tested
  • Resistance to freeze and thaw
  • No deteriorations
  • All four corners are coated with highly visible safety orange for maximum visibility
  • Dampens vibrations
  • compatible with most rooftop materials



  • Material- 100% recycled rubber, UV resistant

  • Base Area = 33.1 Sq. In. (for use in bearing calculations)


Model No.HeightWidthBase LengthWeightUniform Load Capacity (lbs)*
Standard Base


(101 mm)

5"10- 7/8"4.80 lbs2,500



The channel for Cush-A-Block support assemblies includes a variety of options. Strut can be made in special lengths, finishes, and alloys, including:

  • Aluminum
  • Stainless Steel (304 & 316)
  • Unistrut Defender
  • Zinc Trivalent Chromium
  • Pre-Galvanized
  • Hot Dipped Galvanized



Rooftop supports have been tested by an accredited independent laboratory to the following:

  • ASTM D575 Method B- Modified- Compression/Deflection
  • ASTM D1171 Modified- Ozone Resistance
  • Freeze/Thaw Envrionment Simulation


More than 200 pages to explore

Unistrut metal framing channel, fasteners and hardware are the materials of choice for OEMs, contractors and plant maintenance personnel. Download the catalog to learn more.