Owners hurt

In order to ensure the tightness of the windows, it is necessary to cover with cement-sand plaster. The team that is engaged in the installation of windows is not enough time to perform these works. And therefore, they believe that their task is to put the window on the mounting foam, and then let the owners hurt about the tightness of their windows. The best option would be to install windows on a cement mortar. Better yet, demand from the installers of the windows to do their work qualitatively. But this question needs to be stipulated with them in advance, even at the stage of ordering windows.