STP1334: Evaluation of Accelerated Laboratory Test Methods to Predict Sealant Staining of Stone Substrates

    Gorrell, TA
    Senior Architect/Engineer, Vice President and Principal, and Consultant, Wiss, Janney, Elstner Associates, Inc., Chicago, IL

    Chin, IR
    Senior Architect/Engineer, Vice President and Principal, and Consultant, Wiss, Janney, Elstner Associates, Inc., Chicago, IL

    Scheffler, MJ
    Senior Architect/Engineer, Vice President and Principal, and Consultant, Wiss, Janney, Elstner Associates, Inc., Chicago, IL

    Pages: 13    Published: Jan 1998


    Abstract

    Sealants used in joints in exterior walls can cause staining of masonry wall substrates due to penetration of the sealant into the substrates, adversely affecting the appearance of a building.

    The authors have conducted tests to determine if accelerated laboratory testing can reliably predict if a sealant will stain substrates. The testing included commonly available brands of silicone and polyurethane sealants installed in joints between three types of stone substrates. The joints of one-half of the specimens were compressed during the testing. The test specimens were exposed to a variety of accelerated environmental conditions, as well as to a real-time exterior environment.

    A portion of the authors testing was very similar to the testing outlined in the American Society for Testing and Materials (ASTM) C 1248 “Standard Test Method for Staining of Porous Substrate by Joint Sealants.”

    A comparison of the staining of the accelerated test specimens with that of the real-time exterior exposure specimens indicates that the testing performed, one group of which is similar to the ASTM C 1248 accelerated test, is not an accurate predictor of whether or not sealants would stain stone substrates.

    This paper presents the results of the testing, recommendations to minimize the potential of sealant staining on substrates, and recommendations for additional laboratory testing to predict sealant staining potential on stone substrates.

    Keywords:

    accelerated test, dirt, joint, oil penetration, polyurethane, porous, sealant, silicone, stain, substrate, testing


    Paper ID: STP15678S

    Committee/Subcommittee: C24.82

    DOI: 10.1520/STP15678S


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