Best Practices Precast Panel Finish and Maintenance There are a number of variables that can impact overall aesthetic performance of precast panels. Typical and anticipated conditions such as hairline/ stress cracking may occur due to temperature fluctuations (inside/outside), finish type, thermal movement, foundation settlement or shift. As concrete is a porous material, those variables also create opportunities for water intrusion and introduces the possibility for efflorescence to occur. These conditions are cosmetic only and do not affect the structural performance of the panel or the integrity of the building. However, if a condition is observed that appears outside of “normal”, Fabcon is always available to review and discuss. While Fabcon cannot guarantee the performance of paint or the surface preparation completed by others, we offer the following recommendations to help achieve optimal results: 1.
Cleaning Prior to Painting • Cleaning of the building should be completed in advance of painting. With concrete being a porous material, the precast panels may retain water following cleaning. Adequate time should be allotted to allow proper draining and drying of any residual moisture. Proper testing should be conducted to ensure moisture content conforms to the selected paint manufacturer’s guidelines. • If power washing, precautions should be taken to avoid damage to panel finish. A low pressure is recommended and a safe distance from the face of panel should be maintained.
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Paint Selection • For best performance, both prime and top coating should contain elastomeric properties and be formulated specifically for use on concrete or masonry surfaces. • A heavy-duty, UV-resistant topcoat with an integral texture is recommended for best long-term aesthetic performance on exterior precast surfaces. Incorporating texture helps soften the appearance of natural finish variability inherent to concrete substrates. Note that darker-colored surfaces will naturally accentuate the presence of efflorescence. • Elastomeric coatings help bridge hairline cracking and provide better accommodation for building movement. • Although selecting the correct paint products can help reduce issues related to moisture infiltration, excess indoor humidity can allow for prolonged exposure leading to moisture absorption by the panels. It is recommended that conditioned spaces are monitored for proper humidity levels.
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Flashing and Sealing • All precast panel penetrations and exterior attachments should be properly flashed and sealed. (i.e. doors, windows, louvers, MEP penetrations, signage, etc.) • Tops of precast panels are susceptible to water intrusion and should not be left exposed and should receive proper waterproofing and/or flashing.
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Maintenance • Precast wall panels should be included as part of regular, recurring building maintenance and cleaning. This should include cleaning of efflorescence to maintain aesthetics. • Always follow coating system manufacturers’ recommendations when cleaning and maintaining coated surfaces. • Further recommendations and resources for precast maintenance will be included as part of our Project Closeout documentation. We encourage this to be used as a regular reference throughout the building’s lifespan.
8911 Columbine Road, Suite 150, Eden Prairie, MN 55437
800-727-4444
952-890-4444
Fabconprecast.com