Let's be honest: Unless our bathroom caulk falls out completely, it doesn't occur to many of us to replace it—clean it, sure, but replace entirely? Are we gross? Are we going to die tomorrow? Let's explore.
Fresh caulk should last quite a while—in the five year range—but a couple of factors can reduce its lifespan: Using the wrong kind for the job, poor installation, and even house settling can cause it to pull away from the wall and lose efficacy. Look for cracks, shrinking, and discoloration—all signs it might to time to replace. If you don't, here's what you could be living with:
Peeing in the shower: America's pastime. It seems innocent enough (as long as all members of the household are on board) but there's a hidden, stinky cost. Same goes for the caulk around the toilet, especially in families with boys with aiming issues. Fresh caulk is non-permeable, but we've heard that, over time, it can break down and potentially absorb smells. If you are haunted by ghost pee, and no cleaning will completely rid your bathroom of eau de urine, you might have to replace it sooner rather than later. We suggest sooner.
Is your shower plagued by an pink-ish orange slimy substance? It's most likely a bacteria called Serratia marcescens and, much like mold, something to look out for. (It's also got a fascinating history involving "red" polenta in 1800s Italy, if you're up for an interesting read.) Although it most likely won't kill you, it can, according to Wikipedia, cause meningitis, pneumonia, and infections in urinary tracts, respiratory tracts, and wounds. It's also linked to problems with your peepers, so don't go rubbing that stuff on your eyeballs while you are in the shower.
With an aggressive application of a bleach, tea tree oil, or vinegar solution, and regular squeegeeing, try to keep it under control on your tiles—but if that stuff shows up, go ahead and replace that caulk. You can see a pretty fantastic shower "Before & After" over on Door Sixteen, when Anna had a run-in with the nasty stuff.
There are lots of wonderful uses of mold—where would we be without soy sauce, black tea, and Prosecco?—but I think we can all agree that free-range, at-home mold colonies generally count as potentially harmful. We've see it firsthand during the drama of Joseph's bathroom remodel in a previous post. According to the CDC, exposure to mold can trigger all sorts of complaints, including respiratory problems and skin/eye/throat irritation. You'll have to continuously clean the grout, but periodically recaulking all the seams is one of the best ways to clean, refresh (and visually transform) your bathroom for mere dollars. If you do, make sure you use the stuff specifically for kitchens and bathrooms, which should be clear from the label; they have a special additive that helps prevent mold from forming.
Mildew is early stage mold, which is also objectively not-good. If you are Martha Stewart, you wipe off excess moisture after each shower and prevent mildew from forming in the first place. But old caulk gives mildew a special safe space in which to burrow and hide, and, once in there, requires much coaxing to get it to leave. Maintaining the seal between the caulk and porous tile and/or grout is one of the best ways to prevent a full-blown mold situation in the first place.
Your health and well-being is one thing, but there's something else to consider: the health and well-being of your home. When caulk isn't doing its job, water can reach the wall itself, and, depending on when and how your home was constructed, moisture can damage any susceptible material behind the tile and/or bathtub. Hopefully it's some kind of water-resistant, waterproofed backing board, but if it's just drywall (or something worse), you might be looking at some more extensive repairs down the road. Best to keep everything locked up tight by periodically replacing your caulk, before that happens.
In conclusion, never replacing your caulk is: a) decidedly gross; b) potentially harmful; and c) risks the integrity of your home. If it's cracked, peeling away, or shrunken, it's even more susceptible to mold, mildew, bacteria, and/or water. Keep an eye on it, keep it clean and dry, and stay vigilant.