This European Standard specifies a method for determining the in plane initial shear strength of the horizontal bed joint between the prefabricated part of a composite lintel and the masonry above it, using a specimen tested in shear. Guidance is given on the preparation of the specimens, the conditioning required before testing, the testing machine, the method of test, the method of calculation and the contents of the test report. The method corresponds with the method described in EN 1052-3:2003+A1:2006. Guidance is given where the method deviates from EN 1052-3. Therefore each section of EN 1052-3 is repeated given the necessary changes.