How to Caulk a Shower
Caulk is a necessary component of most showers. Effective caulking of tiled or pre-fabricated showers keeps water inside the bathing area and prevents underlying wall systems from becoming soaked.
For showers with existing caulk, removing the caulk is a necessary precursor to applying new caulk. Once the caulk has been removed, caulking the shower is an easy, straightforward project that takes just an hour or so and can vastly improve the condition of your shower.
Where to Apply Caulk in a Shower
- Vertical seams that run from the top of the surround to the shower pan
- Horizontal seams between shower surrounds and shower pans
- Horizontal seams between shower surrounds and shower ceilings (only for surrounds that reach the ceiling)
- Seams at the junction of the tile and shower door tracks
When to Caulk a Shower
For new showers, caulk the shower right after the shower has been installed using a silicone caulk. Do not use the shower before caulking it. For tiled showers, wait until the grout is fully cured and sealed. Thoroughly clean all grout haze first.
Most types of caulk must be applied when the temperature is between 40 and 80°F. Wait until the bathroom reaches those temperatures.
Codes and Permitting
Permits are not required to caulk a shower. If caulking is done in conjunction with a new shower installation or even a major shower remodel, you may need to obtain a permit from your local licensing authority.
Wear eye and hearing protection when removing old caulk with the electric multi-tool. When working with denatured alcohol or mineral spirits, ventilate the bathroom with open windows and fans.
What You'll Need
Equipment / Tools
- Caulk or grout scraping tool for oscillating multi-tool
- Oscillating multi-tool
- Putty knife
- Shop vacuum equipped with HEPA filter
- Personal protection: eyes, breathing, and hearing
- Small sponges
- Utility knife
- Shower caulk
- Mineral spirits or denatured alcohol
- Painter's tape
Remove Old Caulk
Use the caulk or grout scraping tool to remove as much of the caulk as possible by hand. Where you cannot successfully remove the caulk, switch to the electric multi-tool fitted with a scraping blade. Go easy to avoid chipping or scratching the tile.
With the shop vacuum, remove all debris and dust from the seams and work surfaces.
Wearing latex gloves, wet a sponge with denatured alcohol or mineral spirits. Thoroughly clean all areas that previously had caulk.
Add bleach to warm water at a 1:10 ratio to create a mild solution to clean moldy areas. Allow drying for several hours before proceeding to the next step.
For every seam that will be caulked, run parallel strips of painter's tape on either side of the seam. Space the strips of tape about 1/4 inch apart. Press firmly down on the tape with your finger to prevent the caulk from bleeding through underneath.
Cut End of Caulk Tube
Use scissors or a utility knife to cut off the nozzle end of the caulk tube. Cut close to the end for just a thin bead of caulk.
Slowly squeeze the caulking gun's trigger to extrude a bead of caulk in the seam. Make sure that the caulk fully penetrates the seam. Move the caulking gun at a slow, consistent speed along the seam.
When you have finished one seam, tool the caulk with your finger. Wet your finger in a cup of water. Then press down on the bead of caulk and slowly run your finger along the bead to the end. Frequently wipe excess caulk off of your finger.
Before the caulk has dried, strip off the tape from the seam. Pull upward at a 90-degree angle and, at the same time, pull away from the seam to avoid smearing caulk on the shower.
Let the caulk dry for at least two or three days before using the shower.
Troubleshooting Your Shower Caulk Project
- If the caulk dried before you removed the tape, still try pulling off the tape. The tape is able to cut through thin layers of dry caulk.
- For thick lumps of dried caulk, cut carefully with a sharp utility knife.
- If you don't like the sharp contrast of white caulk against the tile, look for tinted caulk.
- You can also tool the caulk with the back of an old spoon for a smoother surface. Some pros even like to use ice cubes, since caulk will not stick to the wet cube.