You've seen the ominous signs of aging caulk. First it was the brown tinge along the edges. Now its smooth and supple skin has turned brittle and cracked, opening the way for stubborn colonies of mildew to take hold, or for water to seep through and turn wallboard and framing mushy. Whether it's around your sink, between a tub and its tile surround, or covering the joints of your shower stall — it has got to go.
Fortunately, caulk is cheap, and applying it isn't difficult. All you need is an hour, a few common tools, and materials easily found at any hardware store. But as easy as it is, you still have to do it right, or you'll be caulking again next year, says This Old House
general contractor Tom Silva. Cost:
See How to Caulk Around a Tub
for full step-by-step instructions.