Method 1: Rout-and-Seal Cracks

  • Routing and sealing cracks can be an effective way to prevent water infiltration in cracks in which a small amount of movement is anticipated due to service loads, thermal effects, or other causes.
  • When routing a crack, the Contractor should use a grinder to create a V-shaped groove, with the crack centered in the groove. Though it can vary depending on the application, the grooves should typically be about 3/8 inch deep.
  • For cracks in which a significant amount of movement is anticipated, bond breaker tape should be placed at the bottom of the groove prior to sealing. The tape must stay at the bottom of the groove in order to be effective. The bond breaker allows for 2-sided rather than 3-sided adhesion, which permits much greater elasticity of the sealant.
    NOTE: Although good in principle, it is difficult to place bond breaker tape in the bottoms of the grooves such that the tape will not move during application of the sealant. If the bond breaker moves up it can reduce or eliminate the bonding surface on one side of the joint, eliminating their effectiveness. When used, the Contractor must take great care to ensure that tape stays in its intended location.
  • After grooving, ensure substrates are clean and sound. Remove any contaminants, including laitance, oil, dust, debris, or other foreign particles.
  • Fill the groove using a preapproved Class 4 low-modulus silicone meeting the requirements of
    DMS 6310
    ,
    Joint Sealants and Fillers
     or Type V adhesive meeting the requirements of
    DMS 6100
    ,
    Epoxies and Adhesives
     as specified on the plans.