From Dan Harding on August 04, 2008 in Bathroom Remodel
Bathrooms are a breeding ground for mildew—especially in the tub or shower area. And issues with old, unattractive, caulked joints are an inevitable problem for any homeowner. If you’re reading this then you probably know what I’m talking about. At certain point it seems that all the mildew removing techniques you can find just don’t seem to work anymore. Soon after this unfortunate realization, you realize that you will have to replace the caulking.
Mildew needs plenty of moisture to survive. Alas, it is the caulked areas of the tub where water, including body oils, soapy films, and shampoo, often pools up, providing the easiest avenue for mildew to grow. Nowadays you can buy mildew-resistant and even mildew-proof caulking to prevent the further spread of our bathrooms’ unsightly foe. These caulks contain significant amounts of mildew killers, or chemicals that slowly seep out of the caulk and poison mildew spores. Nonetheless, before I get too far ahead of myself, the hardest step in replacing bathroom caulking is the first step: removing the old caulk.
Removing the Old Caulking.
There is really no easy way to do this. You will have to get down and dirty on this one. You can use a razor knife, utility knife, or some other scraper to do the bulk of the work. Take pains not to scratch or otherwise damage the material around and beneath the caulk. Sometimes using water can help (especially if it is a water-based, non-acrylic caulk) but I like to score both sides of the caulked joint to see if I can pull the caulking off in long strips. This is more likely to work with silicone caulk and highly unlikely to work everywhere, so be prepared to take your time.
Softening agents, such as the water mentioned above, can help to remove the difficult areas. Acrylic caulks rubbing alcohol should suffice. In either case, the caulking must be soaked for a long period of time (perhaps even a few days) in order to be truly effective. There is no way to soften silicone caulk. I don’t personally know of any effective technique other than bruised knuckles and a some quarters in the “swear jar.”
Clean the Area.
Once the caulk is removed, you will need to do a thorough cleaning job. If mildew is widespread, then you will need to spray with a mildew-killer of some kind. To simply clean up the area you can rub it down with alcohol. The alcohol will take out any remaining soap scum and other residues, but not mildew. It may also be a good idea to vacuum along the joints to get any little pieces of caulk that may be hiding out.
Let it Dry.
Now let the area dry. Drying times are a matter of debate. I would let it dry for at 24 hours before reapplying caulk. Furthermore, if your problem is leaky caulk, as opposed to mildew, then I would increase that drying time significantly (perhaps 2-3 days!).
Once the area is adequately dry, you can reapply caulk. Make sure you use a bathroom tub and tile caulking. There are a variety of caulks available. PVA, silicone, acrylic latex, and siliconized acrylic latex. The argument on which is better is endless, so do some research and decide what is best for your application. When you’ve installed your caulk of choice, let it dry overnight (at the least!).