Caulking a shower is an important home improvement task that helps prevent leaks, mildew, and drafts. Properly caulking your shower can extend its life, improve appearance, and create a watertight seal. This comprehensive guide will teach you everything you need to know about selecting, preparing, applying, and maintaining caulk in a shower.

Choosing the Right Caulk for Your Shower

When caulking a shower, it’s crucial to choose the right type of caulk. The caulk needs to stand up to heat, humidity, and frequent exposure to water. Here are the best options:

Silicone Caulk

Silicone caulk is the top choice for most shower caulking projects. It has excellent flexibility and adhesion, making it ideal for an area with temperature changes and frequent water exposure like a shower. 100% silicone caulk won’t crack or shrink. It’s mold and mildew resistant. Silicone adheres well to ceramic tile, metal, glass, and plexiglass.

Look for “100% silicone” on the label. Avoid silicone/latex blends. Available in white and clear, silicone works well for most applications, but colored silicone caulk is also available.

Latex Caulk

Latex caulk, also called acrylic caulk, works well for interior uses like filling joints between drywall and moldings. It has more limited flexibility than silicone. Latex caulk shrinks and deteriorates faster when exposed to moisture. It is not ideal for wet areas like showers.

If using latex caulk, look for a “mold/mildew resistant” variety, which contains fungicides to prevent mold growth.

Epoxy Caulk

Two-part epoxy caulks provide a durable, waterproof bond. Epoxy caulk has excellent adhesion to ceramic tile, metal, and fiberglass. It can work for high-traffic areas that require maximum strength. However, epoxy caulking is more difficult to apply than silicone or latex.

Prep Work: Cleaning and Removing Old Caulk

Thorough prep work ensures the caulk will adhere properly to the shower surfaces. Follow these steps:

Clean the Surface

  • Use a nonabrasive cleaner or solution of vinegar and water to thoroughly clean the shower walls and tile.
  • Scrub away any soap scum or mildew. Rinse well.
  • Wipe the surfaces dry with a clean cloth. Make sure no dirt or debris remains.

Remove All Old Caulk

  • A utility knife, caulk remover tool, or putty knife can remove old caulk.
  • Score the caulk with the edge of the tool. Pull up the old caulk in strips.
  • For stubborn caulk residue, apply caulk remover or mineral spirits. Let it sit for 15 minutes, then scrub with a brush or sponge.
  • Remove all traces of old caulk for the new caulk to adhere properly.

Make Any Repairs

  • Inspect for cracks, damage, or missing grout. Make repairs before applying new caulk.
  • Use hydraulic cement to patch cracks or holes. Let it cure fully.
  • Re-grout areas as needed with ceramic tile grout. Allow to dry completely.

Mask Surrounding Areas

  • Mask off baseboards, windows, and any adjacent surfaces with painter’s tape to keep them free of caulk smears.

Now the shower is prepped and ready for the new caulk!

How to Apply Caulk in a Shower

Follow these key steps to apply shower caulk like a pro:

Load the Caulk Gun Properly

  • Unwrap the caulk tube and cut the tip at a 45° angle to open it. Insert into the caulk gun.
  • Squeeze out a small amount to ensure you have a continuous bead with no gaps.
  • Insert the plunger fully and smoothly pull the caulk gun handle to properly load the tube.

Start Caulking

  • Begin in an inconspicuous corner. Hold the caulk gun at a 45° angle, tip touching the joint.
  • Keep the tip moving to maintain a consistent bead as you squeeze the trigger. The bead should be 1/8″ to 1/4″ wide.
  • Move slowly and steadily for smooth, neat lines. Don’t rush.
  • Make sure the caulk penetrates fully into the joint, not just on the surface.
  • Apply caulk in one continuous stream, without gaps from stopping and starting.

Seal All Joints and Seams

Apply caulk anywhere water could enter:

  • Where the tub/shower meets the wall
  • Corner joints
  • Around faucets and shower heads
  • Where bottom tiles meet the tub
  • Where walls meet
  • Tile joints if re-grouting wasn’t needed

Don’t caulk over existing mildew—remove it first.

Smooth the Bead

  • Once applied, run a finger over the caulk to smooth it out and help it adhere.
  • Alternatively, use a caulk-smoothing tool or dampened finger.
  • For a clean look, smooth the bead down flush with the tile.
  • Remove excess caulk from the tile or tub surface.

Let the Caulk Cure

  • Give the caulk time to fully cure based on the manufacturer’s recommendations.
  • Silicone caulk usually becomes water-resistant within one hour but takes up to 48 hours to fully cure. Don’t get the caulk wet during this time.
  • Avoid closing shower doors tight until the caulk has hardened.

Patience leads to great results!

4 Tips for Neat, Professional-Looking Caulk Lines

Applying caulk neatly takes practice. Here are some pro tips:

Maintain Consistent Pressure

  • Keep steady pressure on the caulk gun trigger for a smooth flow of caulk. Ease up if needed.
  • Start/stop movements will leave gaps or blobs.

Go Slow

  • Work methodically without rushing for clean results. It’s not a race!
  • Rushing leads to sloppy beads and mistakes. Take your time.

Use Spray Cleaner/Water

  • Lightly mist the joint with spray cleaner or water before running your finger over the bead to smooth it. The moisture helps prevent drag.

Apply Painter’s Tape

  • For straight lines, apply painter’s tape along the joint before caulking. Remove immediately after smoothing the bead.

Patience and practice create professional looking caulk lines. Take it slow!

FAQs about Caulking a Shower

Still have questions about caulking your shower? Here are answers to some frequently asked questions:

How Often Should You Re-Caulk a Shower?

In showers with frequent use, caulk should be redone every 1-2 years. Caulk can deteriorate faster in humid, wet conditions. Inspect annually and re-caulk when cracked, loose or showing signs of mold/mildew.

What Temperature Should the Room Be for Caulking?

Ideally caulk between 50-70°F. If too cold, the caulk won’t smooth out properly. If too hot, the caulk may begin to cure before you finish smoothing.

Can You Caulk Over Existing Caulk?

It’s best to fully remove old caulk instead of layering new over old. However, if the existing caulk is in good shape, you can apply a thin layer of 100% silicone over it. The new caulk won’t adhere as well.

Should You Caulk Before or After Grout?

Caulk joints between tile and tub/walls after grouting. But caulk between walls before grouting. Caulk last to seal the grout lines.

How Long Does Caulk Last in a Shower?

With a good quality silicone, caulk should last 1-2 years in a frequently used shower before needing replacement. Proper prep and application impact longevity.

How Long Does it Take for Caulk to Dry?

Most shower caulk becomes water-ready in about an hour, though 48 hours provides a full cure. Silicone dries faster than latex. Good ventilation speeds dry time; humidity slows it.


Caulking a shower might seem daunting, but armed with the right supplies and techniques, you can do it yourself and save money. With silicone caulk, thorough prep, patience, and proper technique, you can seal your shower surfaces from leaks and create finished looking joints. Consider re-caulking annually to maintain your shower and prevent water damage or mildew growth. Regular caulk maintenance is a home improvement skill that will come in handy!