Introduction

Sooner or later, mold always shows up in bathroom caulking. This article explains how to clean the old caulk out and then recaulk around a shower or tub.

For a Visual Walkthrough of How to Caulk a Shower Bathtub, Watch this Video:

Tools Required

  • Caulk gun
  • Oscillating tool
  • Putty knife
  • Rags
  • Razor scraper
  • Utility knife

Materials Required

  • Caulk containing mold and mildew prevention additives
  • Caulk remover
  • Masking tape
  • Mineral spirits
  • Paper towels

Project step-by-step (7)

Step 1

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.

A person uses an electric oscillating multi-tool to remove old caulk from the edge of a white bathtub, next to tan tiled walls and a silver faucet.Family Handyman

Step 2

Loosen and remove the remaining caulk.

  • Squirt caulk remover on all the remaining caulk and let it do the hard work.
  • Then scrape off all the old caulk with a razor scraper.
  • Wipe with a rag.

A hand uses a utility knife to remove old caulk from the edge where a bathtub meets a tiled wall near a faucet.Family Handyman

Step 3

Clean the Bare Tiles and Grout

  • Once the old caulk is gone, remove any loose grout between the walls and the tub or shower floor.
  • Treat any mold in the grout along the wall/tub gap with a mold-killing product.
  • Scrub the grout and then rinse off the mold killer with water and let it dry.
    • Use a hair dryer to speed the drying.
  • Clean the surfaces one last time with mineral spirits. Let dry.
Step 4

Mask the gap

  • Mask the wall corner gaps first.
    • 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. 
  • Then apply tape to the walls above the tub or shower floor.
  • Finish by applying tape to the tub or shower floor.

A person applies painter’s tape around the edges of a bathtub and fixtures, preparing to caulk or paint, in a bathroom with tan tiled walls.Family Handyman

Step 5

Cut, push and apply

  • 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.
    • Our experts prefer cutting the caulk tube nozzle at a blunt 20-degree angle, instead of 45 degrees. And they hold the gun at a 90-degree angle to the gap while pushing a small bead ahead of the tip.

A person applies white caulk along the edge of a bathtub using a caulking gun. Green painter’s tape lines the seam between the tub and the tiled wall for a clean, precise finish.Family Handyman

Step 6

Tool with your finger

  • 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.

A person applies green painter’s tape along the edge where a white bathtub meets a tiled wall, preparing the surface, possibly for caulking or painting.Family Handyman

Step 7

Peel off the tape

  • Lift a corner of the tape along the tub and pull it off at a steep angle while the caulk is still wet.
  • Then remove the tape along the wall.
  • Remove the tape from the wall corners last.
    • Remove the tape while the caulk is still wet.

A person peels green painter’s tape from the edge of a bathtub, likely after painting or caulking, with a silver faucet and tiled wall visible in the background.Family Handyman