Recaulking a bathtub

It's well known in my social set that you haven't really tested your destiny until you've hacked the mildewed caulk out of a soggy bathtub joint. At that nadir, that desperate plunge to the bottom of the job jar, you discover your true mettle. If you have a mettle already. And if you don't, this job will snag you one.

To start with, sitting fully clothed in the bathtub makes you emotionally vulnerable, because normally the bathtub is a place of reflection and self-pampering. And leg shaving. But now you're here for a different reason.

You've noticed your caulk peeling for weeks, maybe months, staring eye-level at it every time you recline in the tub. You suspect that the tidal waves you create as you lurch upward to exit the tub are conveying sneaky water droplets under the already-lifted caulk, spawning black feathers of mildew growth, wicking moisture into the wall behind the caulk, and even drip-dropping underneath the tub onto the subfloor, turning the aged plywood into dank mush, the perfect lair for mould spores. Ah the pong of rot, you reflect, nasal hairs quivering.

People have improvised with many sharp and spikey objects to remove caulk, including slot-head screwdrivers, kitchen knives, garden implements, carpet blades, nail clippers, spatulas and scissors. None of them work well.

Thankfully, the tool inventors of the world have come up with some modern solutions, but there are still issues. For example, if the last person to apply the silicone sealant was endowed with a generous nature, the bead of caulk is likely to be rather full-figured. Which means specialty tools like the Caulk-Away tool (available nationwide in all hardware stores and home centres) need backup from old-fashioned razor blades.

Another possible problem is that the installer of the vertical tile on the tub wall made the weirdly common error of actually GROUTING the joint between the bottom row of tiles and the bathtub itself. This is irritating. That space should have been left open to receive caulk, not grout. Because grout doesn't flex, and it doesn't seal. Say it with me: Dang.

So if you have the grout-under-caulk problem you're likely to be hacking out chips of grout along with the old caulk, making the job even more of a deep, stinging pain in the carotid artery.

Here are some tips:

1. Set aside at least 3 consecutive days for this job, to allow proper drying and curing between steps.
2. Buy an inexpensive Caulk-Away tool at any home-improvement retailer. Starting at one end of the tub, push the tool along under the old bead of caulk.
3. Clean up any remaining residue with a single-edge razor tool, available in the paint section at the hardware store.
4. Clean the joint with your vacuum's crevice-tool attachment, then swab the joint with rubbing alcohol to remove soap scum, body oils and other ick. (Rubbing alcohol dries quickly and leaves the surfaces impeccably clean so the new caulking will adhere well.)
5. Wait until the joint is perfectly dry. If the joint has been quite wet from a long-failing caulk job, put a fan on the joint and leave it running for at least 3 days to pull all the moisture out from underneath the tub.
6. After the joint is bone dry, fill the bathtub with water.
7. Get into the tub, either nekkid, or wearing tall boots. Apply a fresh bead of silicone sealant to the joint. Use a premium quality mildew-resistant silicone sealant meant for use around tubs and showers (i.e. GE's Kitchen and Bath silicone caulk or LePage No More Sealant Guns, Shower Bath and Kitchen, which comes in a pressurized container so your hand won't cramp).
8. Smooth the caulk with a wet fingertip. Or for a tidier job, use the Caulk-Rite tool, a small rubber spatula set in a durable handle. It creates a stunning bead with no mess or edge marks. You can also use masking tape to keep the joint narrow and elegant.
9. Don't bathe or shower for a minimum of 24 hours to let the caulk cure.

NOTE: The most common error in tub re-caulking is failure to fill the tub first. Water weighs 8 pounds per gallon. When the tub is full of 8-pound gallons, plus your own weight, the bathtub flexes, dropping down and away from the wall and pulling the joint open. Caulking the joint when it's as wide open as it can ever possibly be, makes your fresh caulk job last way, way longer.