MarMac C 990

C 990 compliant butyl mastic sealant.

Premium Grade Black Butyl Based Sealant

MarMac C 990 is a flexible preformed, premium grade black butyl based rope sealant designed to be (when used on precast concrete):

  • Permanently flexible
  • Tacky
  • Resistant to moisture
  • Resistant to deterioration due to exposure of dilute chemical solutions

MarMac C 990 self-seals joints in:

  • Manholes
  • Septic Tanks
  • Box Culverts
  • Concrete Pipe
  • Concrete Valves
  • Utility Valves
  • Vertical Panel Structures

C990 is supplied in roll form with standard sizes of .75″, 1″, and 1.25″.



Meets or Exceeds Industry Specifications AASHTO M-198*

ASTM C 990 Section 6.2

Chemical Resistance:

30 day immersion testing

No visual deterioration
Cold weather flexibility No adhesion loss

No cracking

Wide Application Temperature Range Able to apply under extreme outdoor weather conditions
• Easy application

• Permanently flexible

• No shrinkage, non corrosive, will not oxidize or harden with aging

• Faster installation

• Hydrostatic performance

• ASTM C 990 Sec. 10.1 psi for 10 min


NOTE: The foregoing information is published as general information only. The listed properties and performance characteristics are approximate values and are not to be interpreted as manufacturing specifications.


Tell us about your application and let our experts help find the best solution for your situation—and send you a free quote!

Also ask about MarMac C 877 Type III.

Request MarMac C 990 Info