What is the difference between welded joints and mechanical joints? Is it important?
A. In a window or door with welded joints the various frame, transom and mullion sections are literally heated to melting point and welded together (small gaps inside the section are left for drainage.) Mechanical joints are screwed together. It is generally accepted that welded joints are far stronger and significantly less likely to break or allow in leaks. The manufacturing equipment and the process itself is also very much more expensive for welded products. All manufacturers weld the outer frame and vent sections but some then mechanically joint the transoms and mullions. It is especially common for Mid-rails in Doors to be mechanically jointed because of the cost of the special welding equipment needed for this one task. All other factors being equal, you should go for products with welded joints. Make sure that they are fully welded, i.e., no mechanical joints at all. ^ Top of Page Q7. My windows have little ‘covers’ or ‘cap’s’ fitted at the bottom, about inch wide. Water drips
