I just finished up a second shower tiling project in my house. I was excited to see how much more smoothly my second tile job would go than my first. All was good until the final step of caulking the shower corners where the tiles meet. I decided to use a clear 100% silicone caulk because the corners looked good and I wanted to show them off.

The grout that the silicone has touched is now much darker than the rest of the shower.

I'm obviously disappointed that this happened in the last step of the process. I spent a lot of time planning things out and even spent the extra money on a high quality grout that does not need to be sealed (Laticrete Permacolor Select). I waited several days after grouting to apply the silicone.

I've now waited almost 48 hours and the discoloration is still present.

Has anyone experienced this before? Any recommendations on how to resolve?

I'm thinking about removing the caulk with a razor blade and purchasing a caulk from the grout manufacturer that matches the color of the grout. This would hide any possible staining that clear silicone caused, but I'm hoping I don't need to go this route. In the only other shower I tiled, I ended up having to remove the silicone and add a different color and I'm really hoping that I don't have to go through that again.

  • Have you contacted the grout manufacturer to get their input on ways to darken the rest of the grout? Feb 1, 2020 at 16:59

2 Answers 2


Generally speaking, any time you apply a glossy material over a matte material you get darkening. It's unfortunate that this was discovered now, but you do have options.

If you haven't yet sealed the grout, and plan to, see what that does for the situation. Some sealers won't change the color, but some will. Maybe it'll bring things closer to a match.

Otherwise you'll need to cut away the caulk, scrape off at least the surface of the grout (deeper is better for bonding), and re-grout those joints.

Clear silicone is great for many things, but color-matched caulk is better in this situation, and urethane is the best I've used in terms of grab and durability. Use as small a bead as possible (trim the nozzle to act as a tool and don't "finger" the bead out), and note that urethane does not come off what you put it on. Plan well, wear latex-type gloves and old clothes, and consider masking the tile outside the bead boundaries.

  • You recommend this even though the grout has a built in sealant? This grout has a packet you add when mixing that adds the color and a little pouch that dissolves. It seems like it's the sealant as it's kind of gluey.
    – adivis12
    Jan 31, 2020 at 13:54
  • Nope. I recommend this if you already plan to seal, as I said. The goo you mention may be a latex modifier (for flexibility and bond) and not a sealer, but it may be. Read the box.
    – isherwood
    Jan 31, 2020 at 13:56
  • I wasn't planning on sealing because of the built in sealant, but if that's an option that could solve my problem, I'd consider it. Not sure if a sealant will absorb since there is already a sealant in the grout.
    – adivis12
    Jan 31, 2020 at 13:58
  • And thanks for the recommendation on urethane, but since there likely isn't a color match and the fact that I can't redo it if I mess up makes me nervous. I'm pretty good at the construction side of things but when it comes to the fine details of finishing I have a harder time.
    – adivis12
    Jan 31, 2020 at 14:06
  • 2
    Sure, but I would look at a clear sealer first. You don't want to end up too far from the color you intended. Maybe mix up some grout and build a sampling panel so you're not experimenting on your project.
    – isherwood
    Jan 31, 2020 at 14:35

The discoloration will never go away on its own. You will need to remove the silicone (difficult, yes...) and use the color matching caulk from the grout manufacturer.

In the future - the color matching caulk should always be used in the corners in place of grout so the two walls are able to move slightly (which they will) without cracking the grout in the corner.

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