How to Recaulk Your Bathtub Like a Pro: Stop the Mold in One Afternoon
Moldy, cracked, or separating caulk around a bathtub is one of the most common sources of preventable water damage in American homes. Water behind tile works silently for months, rotting subfloor and wall framing until the damage is expensive to repair. Recaulking a tub takes three hours including drying time and costs about $8 in materials. A clean, fresh caulk line also transforms the appearance of the tub surround immediately.
Remove All the Old Caulk Completely
The most common recaulking mistake is applying new caulk over old caulk. New caulk over old fails faster than either alone. Use a caulk removal tool or oscillating tool with a caulk-removal blade to cut and pry out every bit of old caulk. For stubborn residue, use caulk remover solvent. When you’re done, every bit of old caulk must be gone — no exceptions or the new caulk will separate at those spots.
Clean and Dry the Surface
Clean the joint area with a bleach-water solution to kill any mold spores, then dry completely with a hair dryer if necessary. Wipe the joint area with rubbing alcohol to remove soap residue that could compromise adhesion. Caulk will not adhere to a wet, damp, or contaminated surface.
Tape and Apply
Apply painter’s tape along each side of the joint about 1/4 inch from center. Fill the tub with water before caulking — the water weight expands the joint slightly, and caulk applied with the tub full won’t crack when the tub is used. Cut the silicone caulk tube at 45 degrees, apply in one steady stroke, smooth immediately with a wet finger in one continuous pull, and remove the tape immediately while the caulk is still wet. Allow 24 hours to cure before getting it wet.
