Butyl Sealant

Butyl rope sealant for joints of concrete structures.
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Premium-Grade, Flexible Butyl Rope Sealant

MarMac’s Butyl Sealant (C990) from H.B. Fuller is a flexible butyl rope joint gasket used for sealing precast concrete structures. Butyl Sealant is perfect for sealing joints of manholes, septic tanks, box culverts, concrete pipe, concrete vaults, utility vaults, vertical panel structures, and more. It is also a great choice for sealing the seams of metal sheeting such as roof panels and Morton Building walls.

Butyl Sealant is permanently flexible, tacky, resistant to moisture and to deterioration by exposure to acidic and alkaline environments. It is available in a variety of sizes to fit a the application at hand. It meets or exceeds the ASTM C990 standard for butyl-tapes.

Exhibiting high elasticity and showing no adhesion loss or cracking in cold weather, Butyl Sealant can be applied in a wide range of temperatures and can endure extreme outdoor weather conditions. The flexible tape form makes for a watertight seal and fast installation.

Butyl Sealant is non-shrinking and non-hardening. It is chemical-resistant, showing no deterioration after 30 days exposure, and meets or exceeds ASTM C990, Section 6 specifications for butyl tapes, as well as AASHTO M-198 with the exception of flash point and fire point. Butyl Sealant is not intended for use in expansion joints or joints that move.

Features & Benefits
  • Meets or exceeds ASTM C990 specification
  • Chemical-resistant
  • Permanently flexible, including in cold weather
  • Extreme temperature performance
  • Fast & easy application
  • No shrinkage, non-corrosive
  • Does not deteriorate, oxidize, or harden with age
  • No adhesion loss or cracking
  • Hydrostatic performance
0.75″ 174′ 8
1.00″ 174′ 6
1.25″ 174′ 4
1.50″ * 131′ 4

*Special order only

Meets all requirements of ASTM C 990 Section 6.2. Meets requirements of AASHTO M-198 with the exception of flash point and fire point.

Not recommended for use in areas of concentrated oils or hydrocarbon solutions. Prior to working with MarMac Butyl Sealant, consult the product label and Safety Data Sheet (SDS) for necessary health and safety precautions.

During testing method ASTM C 990 for chemical resistance, MarMac Butyl Sealant (C990) had no visible change after 30 days of immersion in 5% solutions of HCI, H₂SO₄, NaOH, KOH, or H₂S. Upon testing in accordance with ASTM C 765, Butyl Sealant had no sag or shape change after 14 days when tested at 158°F for elevated temperature flow, and did not experience cracking or adhesion loss when tested at -10°F for low temperature flexibility.

Service Temperature Range -40 °F 250 °F
Application Temperature 20 °F 120 °F
Color Black Visual
Hydrocarbon Content 51 % min ASTM D297
Ash Content 35 % min AASHTO T111
Specific Gravity 1.15 – 1.40 ASTM D71
Ductility 5.0 cm min ASTM D113
Compression Index @ 77°F < 100 lbs/in3 ASTM C972
Compression Index @ 32°F < 200 lbs/in3 ASTM C972
Cone Penetration @ 77°F 55 – 85 dmm ASTM D217
Cone Penetration @ 32°F 35 – 65 dmm ASTM D217
Chemical-Resistance* Pass ASTM C990
Low Temperature Flexibility Pass ASTM C765
Elevated Temperature Flow Pass ASTM C765
Flash Point 375°F (191°C) ASTM D92
Volatile Matter by Weight < 2 % ASTM D6
Recycled Content by Weight ≤ 7.5 %

*30-day immersion exposure to 5% solutions of HCl, H2SO4, NaOH, KOH, H2S

Butyl Sealant (C990) should be stored in its original packaging (shelf life 2 years), out of direct sunlight, protected from the elements. Material should be kept away from direct heat, sparks and open flame. For optimum results, store in a tepid (60-80° ̊F) environment prior to installation. Storage temperature should not exceed 120°F (49°C).

The surface of the structure to be sealed should be dry and clean of dirt and debris. Take a roll of MarMac Butyl Sealant from case and avoid touching the sealant to dirt and other materials on the job site to ensure proper adhesion. Apply Butyl Sealant with exposed sealant against the concrete structure and apply around the joint without stretching. Cut to length and complete seal by butting the cut ends without overlapping and molding the ends together. Remove the protective release paper by peeling it away from the sealant. Set the joint properly with the sections aligned and straight. MarMac Butyl Sealant will adhere to the concrete surface and fill the annular space in a uniform manner between the tongue and groove when the pieces are properly joined. MarMac’s RB Adhesive Primer is recommended for installations below 40°F (4°C).


Diameters: 0.75, 1.00, 1.25, 1.50″
Roll lengths: 174, 131′ (1.50″ only)


Manhole Joints
Septic Tanks
Box Culverts
Reinforced Concrete Pipe
Concrete Valves
Utility Vaults
Vertical Panel Structures
Metal Sheeting

Butyl Sealant
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*All statements and technical information are based on tests and/or data which MarMac Manufacturing deems reliable, however, MarMac does not warrant or guarantee the accuracy or completeness of such information. Please read further manufacturer liability and warranty information.

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