Joint Preparation

Joint PreparationDiamond Grinding smaller

1. Sealant and Residue Removal

  • Cut away failed sealant as close as possible to the joint edge and remove all existing sealant and backing materials.
  • Clean all joints of contaminants and impurities to the depth at which the new sealant and sealant backing are to be installed.  This may be accomplished by the following methods:
    • Porous Substrates: Diamond grinding for concrete, masonry,   brick and similar porous substrates to expose virgin substrate.
    • Non-Porous Substrates:  Razor knife for non-porous substrates such as metal and glass followed by a solvent wipe to remove most if not all residual sealant.
    • EIFS Substrates:  Extreme caution must be taken when restoring EIFS joints. Sealant must be removed by razor knife only in order to maintain an undamaged EIFS substrate surface.  Grinding is prohibited.
    • The Pecora Silspan EIFS restoration system may be utilized in order to prevent any substrate damage possibly caused by attempting to remove existing failed sealant.


2. Surface Preparation

  • Blow dust, loose particles and other debris with oil-free compressed air.  Make as many passes with cleaning tools and compressed air as required to ensure that joints are clean and free of existing sealing materials and/or other dirt and debris.

Refer to Pecora Technical Bulletin #109  Surface Prep Guidelines for Silicones and Technical Bulletin #110   Surface Prep Guildelines for Urethanes for more information.


3. Priming

  • Sealant primer may be required and should be determined by the manufacturer or applicator through field and/or laboratory adhesion testing.
  • If primer is required, primer must be installed per the manufacturer’s application procedures in regards to appropriate primer selection, coverage rate, and dry time.

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