There was some mold growing inside the caulk at one corner of my tub so I cut it out. In doing this I discovered I have a few small gaps in the old caulk I'd like to fill.

  1. I want to practice removing/applying new caulk (I am a complete beginner here), so I'd like to do just the front part of the tub. Is this ok? Will there be an issue where the new caulk meets the old caulk at the front-right corner of the tub? (1st photo shows the small gap where I cut out the old caulk where mold was growing).

  2. In the 2nd photo, where the outside of the tub meets tile, it looks like it is caulk but it seems different than the caulk used inside the tub. What type of caulk/sealant should be used here?

  3. For the 3rd photo, what can I use to fill in the small gap where the tub, floor and tile all meet? Is there some kind of very simple pre-made grout I can just use to fill up that hole? Or should I use caulk instead?

Thank you in advance for whoever may take the time to read and respond to my questions.

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2 Answers 2


That is not a bathroom crevice that is a canyon.

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You can not stop water from flowing in a canyon unless you build a big ass dam.

But before that WTF is going on in that tub? HOLY SH!T was my reaction. Nice tile, good quality tub (I can tell its cast iron) and egregious small mistakes. WOW!!

Let me give you the John Madden teleprompter rundown.


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#2 - What? What? What? You have a gigantic crack, a canyon and that canyon is on rails that contains a large river and it is just wide open? This is like Jerry Rice vs SD in the Super Bowl. Touchdown water.

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#3 - I see what you did here. You went Deacon Jones on the water. I will put so much caulk above this crack that it will get a headslap on the way down. Caulking above the crack only works in Australia. That is a DIY fact.

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#4 - The Mike Martz. Your tile and tub is Kurt Warner. Please please coach give me some protection. Wait they are blitzing 6. Well we will run 5 deep patterns and see what happens. Well you don't have time for that you have mold.

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Summary: What must happen, must happen. This is not me speaking to you, it is your tub, your walls, your sanity.

  1. Tub door shall be removed. I would bury it. It wasn't installed right. Get a rod and curtain that will keep the water out of 90% of the places you are having issues with. This door is funneling water EVERYWHERE. It is the Colorado river on steroids.

  2. Grout all of the large cracks between tile and tub once door is removed.

  3. Caulk all of the small gaps (last picture) between tile and tub.

  4. Realize it will take 1 hour to take that door out and 45 mins to grout and 20 minutes to caulk and you probably have a tub running at 95%. It isn't that bad you just have that door sabotaging right now.


A quality tub and shower caulk of your color choice would be good in all the places mentioned. In photo 3, it was probably grout that was in the space between the floor and wall, but on top of that you could put caulk for the benefit of water protection. Best bet is to remove all the caulk, replace with new stuff. You can also get a cheap tool from Wal-Mart, Home Depot, Lowes, Ace, etc...that is for making the caulk smooth and the proper drain degree for the best job. You can also use a finger, but it may still pool and you may have rough spots where you picked up your finger, wiped it off then continued. Not saying the tool will be perfect. Also, when you fill in the gap, I suggest doing 2 passes. One to "fill the gap" and allow it to crust over a bit. This "fill" will shrink a bit and you can press it into the deeper cracks. Then do a final top coat with your finger or the tool. Also, on the floor area, you can get a caulk rope or a tub-to-floor rubber piece that you cut to the length, then clean the area well, fold in half at the score line and install with half on the tub and half on the floor.

  • Hi Jeff, thank you for your help. To clarify, you are saying for the caulk lining the inside of the tub, remove all of that and replace with new, but for the 2 small gaps in photos #2 and #3 I can just fill them in? Or do I need to remove all the existing caulk/grout in line with them? For example, for photo #2, do I need to remove all the old caulk starting from the gap all the way down to where it meets the floor? Also, for the caulk rope, would I fill the gap with caulk first then put the caulk rope on top of that, or is it just the caulk rope?
    – Danny
    Feb 20, 2019 at 20:46
  • Best where water will come in contact to remove and replace. Outside the tub, other than aesthetics, you can just redo it.
    – Jeff Cates
    Feb 22, 2019 at 1:19
  • And the rope would replace the caulk, it's a one or the other thing,
    – Jeff Cates
    Feb 22, 2019 at 1:20

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