5.1 PSA joints are a necessary and critical component of an insulation vapor retarder system and, in addition to knowing the permeance of the vapor retarder being used, assessing the permeance of the joints is necessary to indicate the expected performance of the system.
5.2 Test Methods E96/E96M does not include instructions specific to preparing multiple-piece assemblies such as psa joints. This practice provides those instructions.
5.3 There are a number of variables involved in making a psa joint, and those need to be considered in specimen preparation and data reporting. Such variables include:
5.3.1 Means of applying pressure to seal the joint,
5.3.2 Amount of pressure applied,
5.3.3 Dwell time prior to test,
5.3.4 Backing surface upon which joint is prepared,
5.3.5 Ambient conditions for specimen preparation,
5.3.6 Dimensions of materials,
5.3.7 Configuration of joint,
5.3.8 Dish size,
5.3.9 Test area of specimen, and
5.3.10 Area of joint.
5.4 It is not likely that field-installed joints will achieve as good a seal as those prepared in the laboratory. Field installations can involve extremes in ambient conditions, surface contamination, limited space, varying pipe radii, varying pressure applied, and variation in base insulation density and rigidity.
5.4.1 Results obtained through application of this practice and Test Methods E96/E96M are best used to compare materials and configurations. It is urged not to equate actual field performance with the results obtained in a laboratory setting.
1.1 This practice provides instruction for the preparation of test specimens of pressure sensitive adhesive (psa) sealed joints of the type employed in insulation vapor retarder systems, for subsequent testing per Test Methods E96/E96M to determine the water vapor permeance (“permeance”) of those joints. It does not cover preparation of other types of joints.
1.2 This practice also provides requirements for the content of reports issued in conjunction with Test Methods E96/E96M testing of these joints.