So what preventative things can you do to prevent mold and water issues? You should probably look at maintenance on your home, such as wax rings on toilets. We commonly see when we're underneath houses, toilet areas that have leaks, and if you periodically replace your wax ring on your toilet, that would prevent a future mold or even dry rot problem. And replacing a wax ring is something any homeowner could do by just looking at a simple YouTube video.
Another preventative tip and maintenance tip you can do are the supply lines that supply your sinks and your toilets. Those supply lines should really be braided hoses. Braided hoses last a lot longer. But by looking at these things periodically and maybe even replacing 'em every few years, you're really gonna go a long way to preventing mold and water problems.
Another preventative thing you can do is go on the outside of your home and look at the windows. Look for cracking in the caulking and the seals around the windows. And if there's a problem, you can have those windows re recalled. Or potentially replaced, then that will help prevent a window leak.