Implementation rules for professional joint sealing
The MAIN FUNCTION of elastic SEALANTS in JOINTS is the SEALING against various types of LOADS. A distinction is made, for example, in environmental influences (rain, frost, heat, chemical effects, other liquids, UV, …) and in mechanical influences such as compressive, peel, tensile and / or shear loads! SEALING MATERIALS in the joint area (compulsory joint) of adjacent components can also be affected by a functioning SEALING. This circumstance claims that the basic structure of the joint must be adapted from the beginning according to the needs of the user’s demands. And most importantly, of course, a suitable sealant must be used! In addition, the sealant should be incorporated into the joints with the proper processing technology.
Professional joint based on the definition of the term according to DIN 18 540
DIN 18 540 provides information on the sealing of exterior wall joints with joint sealants in building construction.
As seen in our illustration below, the joint depth (TF) for joint sealing (Fig. 1) in ordinary structures is structurally altered in most joints (compulsory joints), often significantly deeper than initially desired. Therefore, the gap of the joints should be limited in depth with suitable equipment before spraying with sealant, resulting that a functional seal can be made.
For this purpose, the expert preferably uses a special PE round cord (determination of the water absorption of approved backfill material according to DIN 52 459), which he carefully introduces into the joint background. The diameter of the round cord should be about 20% greater than the actual joint width (BF). As a result, the undesired adhesion of the sealant to 3 rigid surfaces can be successfully prevented. Due to the shaping curvature of a PE round cord, a smaller depth of the sealant (TD) is automatically obtained in the JOINT CENTER of the component surfaces to be sealed than at the lateral adhesive surfaces (BH). Through a technically constructed joint construction with a lower material thickness in the center of the joint is achieved that the resistance is at its lowest point here. This ensures that the sensitive FLANKS of the JOINTS during possible component movements are optimally relieved and, as desired, the main load is automatically transferred to the more flexible center of the joints.
GB: Illustration and explanations of technical terms joint sealing
GB: the main function of the elastic sealant is sealing