Abstract: The present invention relates to an adapter (1) comprising a body (2) with support wings (3), a pressure chamber (4), cleaning wings (5), sealing membrane (9) and a joint former (8). During use the adapter (1) is pulled in direction towards the user and away from the joint former (8), so that the joint former (8) is the last one in contact with the joint. Then the cleaning wings (5) clean the surfaces (21) that have been in contact with the grouting and push excess substance into the pressure chamber (4). The adapter (1) according to the present invention is to get the consumption of the grout down, reduce the amount of work and time, and to create an aestethique joint.