Is it grout or caulking? What is the difference?

“I need re grouting around my bathtub. Do you do that?”  Very common question in my line of work. Yet, most of the time that’s not what they needed, they needed re caulking. It is a common mistake and I decided it’s time to help folks learn one from the other.

At first I was going to look up and quote a bunch of resources that would give the technical explanation of what grout does vs what caulk does, what they are made of and where/how they are used. But that is all out there for people to find on their own and get overwhelmed by it without my help!

I would rather make it simple to grasp and easy to remember. If I am not 100% ‘technically’ accurate it will not be in any way that could cause any harm or damage, I promise. My goal is to give you enough of an understanding to effectively ask for further help or research for yourself.

The purpose of today’s blog is two-fold:

  1.  Provide a simple break down on what the difference is between grout and caulk.
  2. Explain why knowing the difference can matter to you.
Grout fills in between tiles. Caulk seals the seams and corners.

Grout fills in between tiles. Caulk seals the seams and corners.

Here are the basics:

Grout is used as filler for the necessary spaces in between tiles. It is hard and ‘sandy’. It can be colored to match or contrast with the tile it is being used with. Grout itself is basically porous but is generally followed up with something to block absorption for longer wear and sanitary reasons. When grout becomes damaged will usually chip, crack or crumble.

Caulk is soft, flexible, rubbery even. It is used most often along the edges and seams where two different surfaces meet. It is water-resistant, the main purpose of caulk is to seal a space to keep water from passing through. Older caulk that needs to be replaced may start peeling away from surfaces or showing signs of mildew or mold. There are a few specialty colors available now for caulk but the great majority that most of us see is white or clear.

The descriptions above should give enough of an understanding to help you take the next step in getting assistance or doing it yourself.

Knowledge is power! What else is important about knowing the difference between caulk and grout?

Some things to know:

Removing grout even if already chipped or broken needs to be done carefully with the right tools and techniques or it can easily lead to chipped and broken tiles!

Grout needs to mixed correctly and applied with special tools. Most grout has a drying time of at least 24 hours and then should have a proper sealer coat.

Grout color can be customized.

Caulking and re caulking can be true ‘do it yourself’ tasks. The only special tool required for caulking is the dispensing gun and even that isn’t always necessary, for some small applications you can get a caulk in a tube similar to toothpaste now.

Good caulking technique can take time to develop, but even a bad or messy looking job can be effective at the very important task of sealing an area when waterproofing is more important than appearance, like inside a cabinet or under a sink.

Removing old caulk can be done without special tools and not much risk to surrounding surfaces, it is also important to do before re applying caulk to any surface. Never just try to put new caulk over old, it doesn’t hold.

Old caulk must be removed or new application will be a waste of time.

Old caulk must be removed or new application will be a waste of time.

Caulk comes ready to apply. Drying time is for caulk is generally 4 hours or less.

Once you know what caulk actually is you will see the many other places it is used besides around the edge of the bathtub or sink; it is used to seal windows, baseboards, outdoor light fixtures the foundations around your house. You may notice it inside cabinets to seal small gaps and holes.

Please feel free to ask questions or make any comments that might enhance this subject. Correct me if I am wrong. Ask me to elaborate, let me know other subjects like this you might like me to cover.

Most importantly please let me know if it helped, as that is my main goal in writing this blog!

Thanks for visiting  The Fix-It Lass!


Oh, and to answer the question: currently I do caulking but not grout….hoping to add those tools and skills to my repertoire very soon!!

Categories: DIY tips, helpful tips, home maintenance, home repairs, kitchen sink, plumbing, Uncategorized | Tags: , , , , , , , , , , | 25 Comments

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25 thoughts on “Is it grout or caulking? What is the difference?

  1. Wow… thanks for explaining, Cass! You’re such a great expert.


    • Thanks Indra! I am hoping to write more posts like this as they occur to me, or even better as they get suggested. Any of my readers with ideas or questions you would to see on my blog please feel free to let me know! Message me directly if you like at


  2. Kim

    That was a huge help. Thanks so much!


  3. Silvia

    That was great information.
    I was wondering about the soft material looking brown and black and a bit becoming loose . No wonder that no cleaner worked on it.– I need the caulk to be replaced. I have a shower with 2 glass doors and 2 acrylic walls on a cultured marble basin. It does look a bit tricky to replace the caulk where the 2 glass doors are compared to the other 2 sides.
    Can you provide information about cost and time estimates? Would a plumber also be doing that work? I live in Fullerton.


    • Thanks for the feedback, Silvia! I wish you were a bit closer to me so I could help you out with the work you need done, Fullerton is about 30 miles from me. I am glad my posting helped you learn a bit more about what you need done.
      Plumbers frequently do caulking as a finishing step to work they have done but it’s probably not best to call on them for re application of it. You might try Yelp or Thumbtack for someone in your area who has good reputation for such work.
      Good luck and feel free to let me know how it goes!


  4. Sybil

    I have a large space between the lip on the back of the tub and the prefabed wall I installed. So the gap in about and inch deep and an inch tall. I tried filling the space with jyst caulk but that didnt work out. Too much space for caulking to keep the seal and even dry fully. I tried caulking rocks into the space. I figure it’ll give it a nice design but mostly take up the space for the caulking to work correctly. That didnt work either. Again some of thr caulking did not dry and some that did shrunk so water could still get in that space. I cant get my gun to just caulk the seam bc I cant get the angle to hit where it needs to. Should I use grout to fill the space and then caulk the seams from grout to tub and grout to prefabricated wall? Or is there something im not thinking of?


    • Adding rocks as a design feature sounds like a great creative solution! However that is where you should have tried using something more like grout or some type of thin set or mortar.
      If you are trying to fill a gap as deep as an inch you can’t just fill it with caulking. Usually any space deeper than 1/4 inch needs to first be filled with backer rod. Caulk is meant for sealing small gaps, not really for filling holes.
      It would really help to see a picture of what you are trying to seal.
      I am glad you asked for advice and would love to help if I can. Any chance you can share a picture?


  5. Eleanor Myles

    We just moved into an older home and the bath tub tile looked cleaned. Once we started using it regularly we noticed there was caulk over the tiles and it was tacky when cleaning. How do we fix it.


    • Thanks for considering me a resource. If it is caulking it should be removable with plastic putty knives or any number of products available at your local hardware store. Without seeing something like this in person it’s tough to give advice other than proceed carefully to not cause damage or create leaks.
      Best of luck to you!


  6. We carry exact color matched caulk to match all of the major grout manufacturers on the market. No need to use grout in any wall corner or floor joint!
    Our Color Sil is 100% silicone and comes in 3 finishes: Smooth-Satin-Sanded to most closely mimic your grout in both color and finish.
    Feel free to order direct. We have no minimum quantity and generally ship within 24 hours of receiving your order. Simply order by the grout manufacturer name and color/#. Don’t know whose grout it is? – NO PROBLEM, send us an email and we will let you know how to proceed… ORDERS@COLORRITEINC.COM
    Color Rite, Inc is an exact color matched caulk manufacturer. We have the caulk you need to make your job look perfect.


  7. Thank you, now I get it!!


  8. Shane (I'm female)

    Hi, I’m going to make a tabletop fountain with stones. To adhere the stones together to shape the surface for the water to flow, should I use silicone caulking or grout/mortar with a sealant afterwards? Thanks


    • Most caulk is meant as a seal to keep moisture out but not intended for being submerged in water generally. There is adhesive caulk but I think to hold stone in a wet environment it’s best to use thinset/mortar/grout. Hope your project is going well!


  9. Ginny

    Thanks for the information! Could I use caulk over chipped grout in the showers if I can get a color match?


    • I am not sure if that would be a good fix. If a customer of mine asked me to do that for them I would decline and suggest they talk to someone with tiling experience. Chipped tiles can be removed and replaced by a skilled tile worker.


  10. I’m installing glass tile in a full-height back splash. I’d like to use a clear silicone material between the tiles. Should I use a clear grout or tile? Would a clear unsanded + silicone caulk be appropriate? Perhaps Laticrete silicone caulk and sealant?


    • Answering questions about tiling isn’t something I am very comfortable with, because I somehow just never got any experience with tiling. But my instinct tells me that silicone between tiles for a backsplash is not a good idea.


  11. Jean

    Hi Cass,
    I try to re caulking my bathtub. When I tried to remove the old caulk, and I noticed I removed several pieces of white hard grout out between the bathtub and tile. The biggest piece size is about 0.19 inches x 0.5 inches. I am wondering if I can re caulking the silicone over it without any water leaking in the future as the gap looks a little too big. Or should I grout the gap instead of caulking?
    Thank you very much if you can reply me.


    • You may be able to fill that extra space with backer rod so the caulking has something to hold onto. If your grout is crumbling or in bad condition you might want to get someone to look at it for best advice.


      • Jean

        Great ! Thank you so much for your promptly response! That is very helpful.


  12. Tabitha Anne Erwin

    I would like to know the difference between caulking and mud. If you can help me decipher between the two i would greatly appreciate that


    • Mud and Thin-set are both used behind or underneath tiles to adhere them to the surface where they are being installed such as the floor or the wall. While Thin-set and mud serve the same purpose in general, they are not the same, and are used in different applications. There is more to it than this, but a really over simplified break down is mud typically is for floors and thin-set is typically for walls. Ask a tile person for more in depth information on those differences.
      The question was to explain the difference between caulking and mud. So here is my usual extra simple explanation. Mud attaches a tile to the surface where it is being installed such as the floor. Grout is then applied to fill all the gaps between the tiles creating a fully sealed surface. Caulking is a rubbery, flexible material that is used around seams like sinks, shower door frames, window sills.
      There are lots of different kinds of caulking for different uses, but this is a simple breakdown to help you understand the basics. I hope this helped!


  13. Pingback: Bathtub Leaking? What To Do - Graham's and Son

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