Can I install standard weight tile on my existing home or do I have to use lightweight?

That would depend on many factors. The biggest concerns are the unsupported span of the rafters and the size of the window and door headers. In many areas where snow load or wind load have already been designed into the structure the additional weight between standard and lightweight roof tile is within the tolerances built into the house. Gambale roof tiles are both strong and light and will be suitable to most re-roofing projects. However, prior to finalizing your tile selection, you should always make sure the weight per square meter of the tiles can be supported by the underlying structure.  more