Why Is There Black Mold In My Shower?

Ah, the bathroom! The one place in our homes where we can just relax, take a hot shower, and briefly forget about all our worries and troubles, while imagining we’re bathing in the warm waters of a tropical waterfall! And also try not to look at the worryingly big black spot in the inner left corner of the shower ceiling.

Shower mold is that one home intruder that won’t leave us alone even in our most private moments. In fact, mold is so much of a voyeur that it prefers the bathroom and the shower more so than any other room in the house. Well, that and the basement, for whatever reason.

Black Mold In Shower

Of course, there is a reason for that, just as there are reasons why there is mold in the shower. And those reasons are surmised with this – your shower is mold’s paradise. Plain and simple. This applies to black mold as much as it applies to any other mold out there – your shower has all the perfect conditions for black mold growth and that’s a fact that we just have to accept.

The Origins Of Shower Mold

Accept, but not reconcile with. Because there are a lot of things to do. And the first is to understand which exactly are those conditions that lure mold so strongly into our shower?

  • Mold loves moisture. It’s as simple as that. High humidity levels are a must for mold growth and that’s especially true for black mold which requires even more moisture than most other types. And while in the rest of the house it is relatively easy to control the relative humidity – either by proper ventilation, by using an air conditioner or with the help of a dehumidifier – the bathroom is a bit more tricky. Yes, there are bathroom dehumidifiers and we have even written articles about them, but still – the levels of moisture will simply always be higher than in the rest of the house. With proper ventilation and a dehumidifier you can hope to bring it down to an acceptable mold-defying level, but that’s not an easy task.
  • Mold hates sunlight. A lesser known fact, but mold, including black mold, doesn’t actually thrive too well under direct sunlight. Or, to be more precise, it dies from ultraviolet light. And of all the rooms in a house or an apartment, the bathroom is the one with the least amount of sunlight. Even the garage and the basement usually have more direct sunlight, although it’s usually not enough either.
  • Bountiful oxygen is another necessary condition for oxygen. Unfortunately, we can’t really deprive our bathroom of oxygen, as it is a part of our house. After all, are we supposed to shower with a diver’s water bottle strapped to our back? Oxygen is an unescapable mold-friendly condition, however, mold sealants use mold’s need for oxygen by completely sealing it and putting it in a dormant state. The mold can stay in that state for literally millions of years, however, as long as the sealant over it holds, it won’t spread.
  • Like all other living things, mold needs food. And black mold is one of the most gluttonous types of mold out there. Unfortunately, the bathroom also offers plenty of food sources for mold. The dietary preferences of mold can be described as such – “everything that contains organic material”. Particularly substances that are high on cellulose are big favorites of mold. This puts at the top of the list things such as cardboard, wood, particleboard, straw and drywall.
  • At this point you might wonder “Why the shower then?” and that’s a valid question – there is hardly any wood or cardboard in the shower. However, there is plenty of grout between the shower tiles and there is also plenty of hair, body oils, soap scum buildup and other common cellulose materials. All this makes the shower a buffet that no mold, black or otherwise, would think to pass up.
Black Mold On Tiles

So, the answer to the very painful question “Why is there black mold in my shower?!” is simply – it likes it there. You made your bathroom nice and cozy for mold guests. And some of this is not your fault – after all, you are bathing there, of course it is going to be humid. Plus, the bathroom isn’t really a room that you want to put big windows in, right?

Getting Rid Of Shower Mold

Yet, there are things that you can do and we already mentioned some of them:

  • Reduce the levels of relative humidity in the bathroom as much as possible. You are taking long and enjoyable showers there and that is fine, however, make sure to allow for proper ventilation as well. Whether it’s through small windows, the whole-home air conditioning unit, and / or by leaving the bathroom door open throughout the day, the air must flow, plain and simple. If that’s not enough, consider a dehumidifier. There are both big stationary models that connect to the whole-home A/C unit and help dehumidify the air in the entire house, as well as small portable models that can be placed in the bathroom and work there. If you are looking for possible solutions, we have a list of bathroom dehumidifier suggestions that you can check out.
  • Maintain good housekeeping duties. As with anything else in the house, maintenance is the best thing you can do for proper prevention. Clean your bathroom regularly, make sure that everything is working well and clean any dirt or mold spots the moment you see them with suitable mold removal products. A small mold spot is the easiest thing in the world to clean. However, if you leave it up then one weekend out of town later this same thumb-sized spot can grow into several dozen inches wide infestation that you are going to throw your sweat, tears and wallet at to fix.
  • Keep the pipes and shower drains working as efficiently as possible. Clean them regularly and make sure that nothing shady isn’t forming on them. The shower head, in particular, is not the most common place for black mold growth, but it is very suitable for other types of mold like white mold and pink mold. And the shower head is the part of the shower that is actually the closest to your body – you want it to be clean and mold-free, right?
  • Painting over mold with suitable mold paint can work for areas that aren't tiled such as ceilings and walls.

Also keep in mind that simply fanning and disturbing the mold won’t deal with as much as it will aerosolize it and make it spread to other parts of the house as well. When faced with a significant mold infestation, particularly in the shower, sealing off the bathroom while you combat the intruder is a good idea. And that includes the air conditioning access. It also makes dealing with the mold trickier, however, since you want the area to be properly ventilated.

Simply put, it’s best to try and avoid the whole thing from happening in the first place.

Common Forms Of Bathroom Mold

So, which are the types of mold that most often plague our showers?

  • First, we have everyone’s favorite and the one most people ask about – black mold. Black mold is a frequent shower guest. Black mold needs abundant moisture, significant food sources and a long time to develop. This makes it more likely to appear behind a wall than on it, however, if the maintenance of the bathroom is poor enough and it isn’t cleaned regularly, black mold can easily occur. Don’t panic though, bathroom black mold is almost never toxic, as toxic black mold requires some other conditions to thrive as well. Yet, as any other type of mold, black mold can present a clear danger to your respiratory health, as well as to your property.
  • Pink mold is one that people rarely talk about. This may be because it’s not actually a fungus – it’s an airborne organism also known as Serratia marcescens. It’s a bacteria that is very common in bathtubs, showers bathroom tiles and grout.
  • White mold is that feathery powder-like texture that you sometimes see on surface paint, ceiling tiles, wood, carpet, drywall, or insulation. Most white molds belong to the Aspergillus or Penicillium genus and are very potent when it comes to producing airborne toxic pathogens through their spores. When looked at from up close, white mold is very clearly spreading outwards from the surface, always ready to get into the air. Due to its color it is sometimes easy to miss until its spores are in the air and start worsening your family’s health and respiratory conditions.
  • Green molds are the most common types of mold. They are easy to notice but hard to distinguish. Also, they thrive very well together with black molds.
  • Red molds are also frequently found together with green and black molds. However, they are a bit harder to spot and as a result are often left ignored when their green and black brethren are being eradicated. This is bad, however, because red mold can be just as dangerous as the rest of them.


So, as you can see, your shower and bathroom are great breeding grounds for all the different kinds of mold and proper prevention and maintenance are your best bet against them.

Once you have rid yourself of your mold problem, be sure to paint your walls with suitable mold and mildew resistant paint to prevent it from coming back. 



About the Author Lets Remove Mold

If you're looking to buy a new dehumidifier then you're in the right place. Through years of HVAC and mold remediation experience, the team at letsremovemold.com are able to provide advice on the type of dehumidifier you need for your home.

follow me on: