Associate Consultant, Construction Consulting Laboratory, Ontario, California
Pages: 11 Published: Jan 2004
A durable building seal requires full and continuous adhesion of the weatherproofing sealant in the joint at all locations. At times, mere nominal adhesion is achieved. Reasons for nominal adhesion will not be discussed here, but they vary widely. This condition is not easily detected, and traditional methods of test verify adhesion to the substrate, not the continuity of the seal itself. The result can be leaky buildings despite successful intermittent field “pull testing”. The challenge becomes finding and repairing sealant beads that may not be visibly failing.
This paper makes a case in support of the recently published “Standard Practice for Evaluating Adhesion of Installed Weatherproofing Sealant Joints” (ASTM C1521-02). The practice describes a nondestructive procedure that places a strain on the sealant and a stress on the adhesive bond. The procedure consists of applying the strain to the sealant bead using a “blunt dowel shaped probe”. Use of this dowel shaped probe is subjective, however, and is wholly dependent on the user to gauge the appropriate strain required to obtain an appropriate elongation.
A device has been created that is able to comply with this non-destructive procedure in a uniform and controlled manner. This paper describes the device and its workings. Additionally, a detailed description of the process by which the device has been calibrated to the properties of a variety of sealants is presented. Finally, reports of the successful field use of the device are given.
In conclusion, this paper asserts that the future of field-testing of sealants will necessarily include non-destructive procedures that have the ability to test 100% of installed sealants. This approach to field-testing will provide all concerned with a new level of confidence that a durable building seal can be achieved.
sealant, adhesion, non-destructive, testing device, field-testing, toxic mold, ASTM C1521
Paper ID: STP12573S