Polish export of windows made of is one of the biggest in the world. Achieving such level would not be possible without relevant management of the process of preparation of windows construction for their transport. One of the main factors that determine the construction quality is the method and the conditions of the thermal joining of profiles in production. The article describes two methods of thermal joining and then analyses their application in the production process with parallel presentation of strength tests. Strength tests are connected with the implementation of the construction from polyvinyl chloride (PVC) – white and coloured in mass as well as composite structures made from polyvinyl chloride and polymethyl methacrylate (PVC+PMMA). Summarizing, the article presents chosen methods of windows construction protection in transport.