Heritage and Authentic sash windows have the option of choosing diagonal welded joints.
While many are happy to install grooved joints, some installers ask for polished joints. These can be done, however, we do not recommend polishing PVC-U because you must start the polishing process by scouring the extruded gloss surface, which is impossible to get back. Dirt tends to gather on the polished joints and soon looks grubby. Foil profiles are not grooved but have a knife finish.
