My wife and I just bought a house, and I noticed after using the shower, there were black specs all over the shower floor. There is a seam where the bottom part of the shower joins with the wall covering, and there is no caulk. I sprayed water into it, and a nearly endless stream of black and yellow specs poured out. Should we remove the enclosed shower and check for mold? Some people online claim that this is soap scum, but there are a lot of seams in the shower without caulk so I am concerned it could be mold.

This what was coming out at the hour mark. Here is a video: https://youtu.be/PW_0p61zcHY

2 Answers 2


First go to a home store and look at how this style tub and shower surround are built. Next realize the tub has a lip that extends up and the bulge at the base of the surround is to overlap the lip on the tub.

If you want to purchase a new surround try removing it, You have probably shot some water up inside the wall and that can cause mold.

If you want to keep mold from becoming a problem seal the joint with a latex calking or any silicone bathroom calking with mold inhibitors.

Whatever you do don’t pull the drain and see all the gunk hair and? in the drain or you may want to move out.

Seal the joint and forget about it would be my advice.

  • Thanks. We were hoping that would be enough. Commented Apr 16, 2020 at 2:38
  • One of the bathrooms in my current house has this exact style tub, it failed inspection or would have , the calking was all loose like it did not stick. I told the inspector I would fix it , he laughed , I pulled it out went to my truck and had a tube of call and filled it in maybe 2 minutes , he crossed that off. Not a big risk here.
    – Ed Beal
    Commented Apr 16, 2020 at 2:44

If the only source of water is that seam then you might be alright; mold (both black and wood rot) needs suitable water, food, temperature and oxygen to GROW (they can still survive in many cases). If you remove the source of water the mold will stop growing.

Not all mold is bad for you, not all black mold is bad for you. It may depend simply on if it effects you or not. More information at the CDC

Wood rot will cause structural issues. How bad of an issue depends on how much decay and how 'important' the structural item.

While you might be ok sealing the seams, I think that you need to both see if there is structural damage and deal with the mold more directly. This will require removing the shower enclosure at a minimum, then deal with the issues that are found, of course

  • Really there is a lip on the tub , someone suggesting to remove a surround has not done many or any bathrooms in my opinion-
    – Ed Beal
    Commented Apr 16, 2020 at 2:16
  • Thanks for sharing your opinion about my expertise related to the validity of my answer. Where do I say that there is no lip? One of my first carpentry / remodel jobs back in the day was for a company that did many surround installations, so I am familiar with them. I understood from your answers here that you are an electrician? I looked at the video again and yes, I agree that this is indeed a tub and not a shower. But that doesn't change things and I stand with my answer. The shower surround in my stand up shower has a seem between the enclosure and the pan at about 3" up.
    – Ack
    Commented Apr 16, 2020 at 3:32
  • You are right I am a licensed electrician and universal HVAC but I have been in general construction most of my life (electrical pays better) , I have tiled thousands of square feet over the years because my dad a contractor that I worked for hated tile so I got all of those jobs before he passed at a young age.
    – Ed Beal
    Commented Apr 16, 2020 at 13:27
  • I'm sorry about your father, that's tough. I see no reason why you downvoted me or made the disparaging comment, where is my advice off according to you?
    – Ack
    Commented Apr 16, 2020 at 13:38
  • Having a new DIY looking for structural damage in this case was two far in my opinion, at least I state a reason why a down vote was given some do not and nothing is learned , that’s why I reverse downvoted that do not have a reason unless it is painfully obvious.
    – Ed Beal
    Commented Apr 16, 2020 at 14:05

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