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A Beginner’s Guide to Caulking a Bathtub

I like working on DIY projects and like sharing my knowledge with others.

Caulking is one of the simplest ways to make home improvements that not only look good, but serve an important purpose, such as preventing water damage.

This tutorial uses the tub and shower as a way to illustrate how easy it is to do your own caulking. Caulk is used in a variety of places from windows, tubs/showers, and kitchen back splashes. Though some tips are specifically for the tub and shower, most of what you will learn here can be applied to almost all caulking situations.

The white bath/kitchen caulk, the gun, blue painters tape, utility knife, and a washcloth. Missing are the paper towels, which come in quite handy for cleanup.

The white bath/kitchen caulk, the gun, blue painters tape, utility knife, and a washcloth. Missing are the paper towels, which come in quite handy for cleanup.

Supplies Needed for Caulking

To get us started, we need to purchase or gather the necessary supplies. We are assuming that there is no caulk already present, or that it has already been removed:

  • A caulking gun.
  • A tube of caulk. Caulk can vary depending on what it is used for. Make sure to get a caulk that specifies use for a bathroom or tub and shower. The color may vary as well, so choose a color that matches your tub or shower. I use a fast 3-hour drying 100% silicone white caulk.
  • Painters or masking tape. Tip: the blue painters tape makes it easier to see your work due to the contrasting colors.
  • Rags and/or paper towels for keeping yourself clean and not so sticky.
  • Optional: A sponge and some rubbing alcohol to clean the surface that will be caulked, and a hairdryer to dry the cleaned area faster.

Prep Your Tub for Caulking

After you have gathered the supplies, we must prep the area we will be caulking.

  • Optional: I rarely if ever complete this step in its entirety, but you want to make sure that the surface you will be caulking does not have dust, mildew, or existing caulk bits. To ensure a nice clean surface take a sponge and some rubbing alcohol and clean the seams and the edges around the seam in which you will be caulking. I typically use a water wet rag and let dry. You can also use a hairdryer to speed up the process of drying.
  • Grab your tape and begin cropping around the area you will apply the caulk, taping below and above the tub and shower seams. The width of the seam is for your discretion, but realize that a caulking seam that's too small may result in the caulk not attaching to the tub or wall surface causing cracks where water can seep in.

Prep Your Caulk Gun

With the tub ready for caulking we must now ready our caulking gun.

  • Remove the cap from the caulk.
  • Cut the tip of the caulking tube. Check the point of the tube after removing the cap to find measurements for bead sizes depending on where you cut, the size of bead is at your discretion, but as a beginner a smaller size may work better for control (mine has 1/8, 3/16, 1/4, 5/16). Choose your size and using a utility knife, cut a 45° angle and the tip of the caulk bottle where you removed the cap. This angle will allow you to lay good caulk beads in the seams.
  • Puncture the seal of the tube. If you look inside the tip you just cut you will see a foil seal, which needs to be punctured in order for the caulk to be released. Some caulking guns have a small puncturing tool attached to them, so check your gun before stabbing anything into the caulking tube. Remember, whatever you use to break the seal will probably end up with caulk on it, and it may not be fun to clean off.
  • Pull back lever arm (in the shape of an L at the back of the gun). It should snap into place once pulled all the way back, resulting in a space for you to insert the caulk.
  • Insert the caulk bottle, with the circle at the end of the 'L' arm of the gun resting inside the hole at the butt of the bottle of caulk. The tip of the caulk bottle rests in the notch at the front of the gun.
  • Grip trigger to solidify a grip on the caulk bottle.

How to Caulk Your Tub and Shower

We are prepared and ready to go. Our tub is taped up, our gun is prepped. Just a final few things to do before we get caulking.

  • Tear off a few sheets of paper towels to wipe your fingers and hands off from big messes.
  • Get a washcloth wet and ready for washing off your hands after getting your hands wiped off using the paper towels. Too much caulk on the washcloth will render your wash cloth useless.

Alright, we are ready!

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  1. Begin by starting at one edge of the tub. Place the tip of your caulking tube into the crack between the two pieces of tape. Make sure the tip of your caulk is facing down into the crack, and keep your gun at about a 45° from the crack.
  2. Press and hold down on the trigger and begin moving down the seam slowly. Don't worry about putting too much or too little, we can always try again and we will be using our finger to spread the caulk evenly.
  3. Do one edge, then use your finger to wipe slowly and lightly to pull the caulk down the seam. You will notice that this will pull some extra caulk and cover past the point you stopped, hence why I wait and do only one edge or a small section at a time.
  4. Continue this process, adding more caulk if you feel it is too light or you feel you messed up.
  5. Once you have completed, pull the tape away slowly and dispose of quickly. Make sure to be careful when doing this since there is caulk all over the tape and could get all over you and the tub.
  6. From here you can either leave it if you like the edge left by the tape, or you can use your finger and go over it again to soften the edges.

Cleaning Up

  • Silicone is a sticky mess, hence why I use both paper towels and a wet washcloth.
  • During the caulking process you will inevitably get your fingers in some caulk. Use a paper towel to wipe away the bulk from your fingers, and the wet wash cloth to get the rest off.
  • In the event you get caulk on the tub or floor, use the same method of using a paper towel to get the bulk, and a wet wash cloth to get the rest.
  • I bring a bucket or a wastebasket to promptly dispose of tape and used paper towels. Tossing them elsewhere will result in a mess of caulk all over the place.
  • As for the caulking tube itself, clean off the tip, place the cap back over the tip and squeeze gently on the gun trigger for a second or two. Make sure not to squeeze too hard or too much as this will cause the caulk to squeeze out of the cap. Doing a nice gently quick squeeze allows the cap to seal and keep the caulk from drying out. Then release the 'L' handle that is holding the glue in place to take the tube out.
Mission accomplished.

Mission accomplished.

The Finished Product of a Newly Caulked Tub

Congratulations! You have successfully completed caulking your tub and shower. Now that you have this new found talent, there are so many other things you can caulk!

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.


jim on October 29, 2018:

i was always told to fill the tub about halfway with water before you caulk. when the tub is full of water, the added weight actually put pressure on the seams.

daisyjae from Canada on January 11, 2014:

You make it sound so easy! I am about to caulk my tub tonight and I am a bit nervous, I hope it is as easy as you make it sound!

Better Yourself from North Carolina on April 03, 2013:

Great hub, very clear and informative. We are in need of caulking some tile in our bathroom and this will really come in handy as it isn't something we have attempted before. Thanks for sharing this!

Jan on January 10, 2013:

Just did my tub last night and this morning it still looks yucky...the caulk dried CLEAR! I did try to remove all old stuff and sprayed bleach solution but the black stain persisted. I think while it is fairly fresh I will start over and follow your directions....I will go purchase a white caulk this time ...thanks...wish you were here!!

India Arnold from Northern, California on March 21, 2012:

What a helpful step by step photo guide for re-caulking a bathtub! I will be using this should we ever need to at a property or in our home. Nice hub! Up across the board!


Robin Edmondson from San Francisco on March 10, 2012:

Wow, what great tips for caulking a tub. I think that we should do this soon in our girls' bathroom. I will definitely reference your Hub when we do. Thanks for including all of the pictures, it really helps!

Glen Nunes from Cape Cod, Massachusetts on March 09, 2012:

I actually have to do this soon (for the first time). This will be helpful. Thanks for the tips.

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