In the Nick of Time
If there's water pooling around the base of your toilet, chances are good that you're dealing with a seal failure. If you're not sure, here's how you can tell: Mop up the water and dry off the toilet. Watch for more water. If it seeps out from under the toilet, it's a pretty good bet that the wax seal is shot.
A Fine Mess
A little bit goes a long way with closet bolts. Don't tighten them down too firmly. Doing so can crack the base of the toilet. If this happens, you'll have to buy a new one.
Toilets are pretty durable things, but they can spring leaks. The good news is that toilet leaks are fairly easy to fix, and are definitely within the skill range of many, if not most, homeowners. The bad news is that toilet leaks can cause big problems if they go undetected, which many of them do. Failures in the wax seals that help secure toilets to floors are at the root of most toilet leaks.
Sometimes fixing a leak just takes tightening up the bolts—they're called closet bolts—that anchor the toilet to the floor. This is a good place to start. Simply use a slotted (flat-head) screwdriver or putty knife and pry off the decorative caps that cover the bolts. Next, tighten each bolt a little at a time with a wrench. Don't tighten one bolt completely, and then move on to the other bolt. This can make things worse. Instead, tighten one a little bit, then switch to the other one. Keep switching back and forth until they both feel tight and secure.
If tightening the bolts doesn't stop the leak, you'll have to replace the wax gasket. This also isn't that tough to do, but it might warrant calling in a plumber if you're not handy. You'll probably need help moving the toilet around. Also, it requires pulling the toilet off the floor, which can expose you to some sights and smells you may not want to encounter. Again, not a bad reason for calling in someone else. If you decide to do this fix yourself, you'll need to buy a few things. Here's your shopping list:
A wax gasket. This is a simple, ring-shaped piece of wax. A newer design incorporates urethane foam and wax for a tighter fit. The choice is up to you as far as which one you want to use.
Mounting bolts. You might end up having to hacksaw through the other ones. Might as well have new ones on hand, just in case.
Mineral spirits or rubbing alcohol, if you don't have any on hand.
Small putty knife.