Similar to our point about less seams on metal roofing, the same can be said in general about entry points. It’s a common misconception that leaks occur because something has broken or created a hole in your roofing. Sometimes, it’s simply a case of water leaking through entry points that were always there.
Now, metal roofing also has a lot of entry points too, such as the spaces where panels join, gutters, and around other penetrations like chimneys and ventilation. However, tiles have an incredible amount of potential entry points too, because there are just so many of them.
In both cases, it’s important you only deal with qualified, experienced roofing contractors, because many leaks are simply a case of poor installation.