January 06, 2021

Expansion and Control Joint Restoration Recommendations and Procedures

Pecora has developed an extensive library of printed and online content that highlights various construction projects, discusses tips and tricks for working with products, and answering some of your burning questions about the industry. Previous Pecora blog posts have focused on offering tips and procedures when working with new construction. When it comes to restoration projects in terms of sealants, there are a whole other set of different dynamics and processes. The first blog post of 2021 will highlight the necessary steps to take when working with sealants on a restoration project.

The first step in any restoration project is to assess the condition of the existing sealant. The primary reason for replacing an existing sealant is performance failure. Performance failure is indicated by cracks within the sealant or at the sealant/substrate interface that penetrates the entire thickness of the sealant. Such cracks will allow water penetration and render the seal ineffective.

The next step is to determine what type of sealant is currently installed in the expansion or control joint you are looking to replace. This is important to ensure the correct restoration sealant is selected for the project. Pecora can assist with sealant identification utilizing state-of-the-art laboratory analysis at no cost to the customer. Once the existing sealant type has been identified, a Pecora representative can assist in the selection of an appropriate restoration sealant.

After the appropriate restoration sealant has been identified, the next step is to remove the existing sealant and proceed with the necessary substrate preparation. In most cases, the sealant is cut out and completely removed from the joint. The exposed substrate will then be cleaned thoroughly to expose a fresh surface. The cleaning method employed will be dependent on the substrate involved. Please refer to the table below with further substrate preparation guidelines.

1In cases where existing sealant is adhered well to substrate and the sealant restoration system recommended will adhere to the existing sealant; a 1/8-inch-thick bead should be left remaining on the substrate.

2Mechanical abrasion can consist of wire brushing (power or hand), saw cutting, or abrasive grinding

3When wet sawing is employed to abrade and clean joint, it may be necessary to use a pressure washer to remove residual masonry material.

4It is sometimes necessary to use a mild abrasive cloth such as Scotchbrite along with a cleaning solvent to remove residual sealant. Always follow solvent manufacturer’s safe handling recommendations and local, state, and federal regulations regarding solvent usage.

After joint substrates have been properly prepared, the recommended backer rod and/or bond breaker tape should be installed. If a primer has been specified or required, apply and wait for it to dry before installing the sealant. Finally, tool the selected restoration sealant to specification as soon after application to ensure proper sealant-substrate contact.

For more information, sealant application recommendations, or information on the installation procedures, please contact our Pecora Corporation Technical Services Group at or call (800)-523-668

Frontier Bank in Lincoln, Nebraska. Restored by JEM Restoration Service, Inc. using
890FTS Field Tintable Non-Staining Silicone Sealant.


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