Caulking is a necessary part of owning a home and sooner or later mold always shows up on bathroom seals. With these tips, anyone can replace the caulk around their tub and shower with some careful preparation and a little elbow grease.
Cut and peel the old caulk. Slice through the caulk along the walls with a utility knife or with an oscillating tool equipped with a flexible scraper blade. Then use your knife or tool to scrape along the tub or shower floor.
Mask the gap. For DIYers, we recommend masking the gap. It takes a bit more time, but you'll get much better results than caulking freehand. Start by finding the largest gap between the tub/shower and the walls. That gap dictates how far apart you must space the two rows of tape. Mask the wall corner gaps first. Then apply tape to the walls above the tub or shower floor. Finish by applying tape to the tub or shower floor.
Apply the caulk bead. Cut the nozzle tip to match the gap width. Hold the gun at a 90-degree angle to the gap and push a bead of caulk slightly ahead of the nozzle as you push the gun forward and continue applying pressure. Apply only enough caulk to fill the gap.
Shape the bead and remove the tape. Wet your finger with water and start at an outer corner. Wipe your finger across the caulk to create a rounded bead and remove excess caulk from the gap.
Don’t buy the wrong caulk. Always use kitchen and bath caulk in a tub or shower. It contains mold and mildew inhibitors that are not present in other types of caulk.
Don’t caulk on top of old caulk. New caulk doesn't bond well to old caulk, especially if the old caulk contains silicone. Just like with painting, better surface prep provides better results.
Remove mold on grout near the caulk areas. Grout is porous, and any mold present in the grout above the caulk line will eventually spread down into the new caulk area and destroy the bond.
Don’t cut the nozzle larger than the gap you're filling. A larger opening applies too much product, making it harder to tool and clean up.
Make a clean cut on the tip. Always cut the tip with a sharp utility knife rather than the cheesy guillotine mechanism built into some caulk guns. Remove any burrs with a utility knife or sandpaper before caulking—the burrs will create grooves in the caulk lines.