Subtle plumbing problems can be the most dangerous for homeowners. They can infiltrate quietly, waiting for the right moment to strike—like when you've just returned from a weeklong trip and wonder why your home smells so musty. Or when you (not your home inspector) discover that your drywall has been home to mold for who knows how long. Sneaky plumbing problems can cause costly damage and inconveniences, but they're not always easy to spot. One influential factor that does give you some predictive power when it comes to plumbing problems is the age of your plumbing system. The reality is that the older your pipes are, the more likely they are to have problems—serious problems like leaks and corrosion. Regular inspections of your plumbing, especially if it's on the older side, can weed out areas of concern and (hopefully) save you a headache or two down the line.
Another common plumbing problem is inconsistent water pressure, and it can result from several factors. When your water pressure changes, it might mean you have a blockage somewhere, a leak you can't see, or a pressure regulator that's gone wonky. No matter what, your plumbing system isn't working as it should, and some amount of water is almost surely being wasted. And if your water pressure's low, you might just think, "Well, this is how my house is now." But if it's low, the significant chance exists you have a substantial leak somewhere, or your pipes are damaged. And if it suddenly spikes (or if you have any other plumbing problem), and what's pressing against your plumbing system will likely find a weak point in it somewhere.
Frequent drainage problems signal plumbing troubles and can often be traced to blockages or inadequate slope in the drain pipes. When water drains slowly from a sink, tub, or shower, when it seems to be almost at a standstill, and especially when you hear the gurgling sounds from within the toilet, it's a pretty sure sign that something is stuck in the drain somewhere, or that the drain itself has some kind of defect. Over time, the "growing" drain has become almost a manifesto of the accumulation of everyday materials that are not meant to be inside the drain in the first place. Soap scum, hair, and grease indeed may be the three most common "secret" agents of the clogged drain. And they (or any of the other "secret" agents that the next chapter will reveal) can form an intense and tough block in the pipes. If water can't flow down the drain, then something must be forcing it to not do so.