Shower Mold Causes and Remedies – Ask a Vancouver, BC Mold Specialist

Answering More Questions about Mold with David Fairbairn

Mark: Hi, it’s Mark from Top Local Lead Generation. We’re here with Vancouver Home Inspector and Mold Specialist, Mr. David Fairbairn of Fairbairn How are you doing today David?

David: I’m doing really good, how are you Mark?

Mark: I’m good, so we’re going to talk about shower mold today, the causes and remedies, what’s the deal with shower mold?

David: Well, I’d like to talk about shower mold and I hope you’re ready to see some photos of said mold, Mark. It’s kind of a common problem we have in homes especially you don’t have to have a flood or a leak to get shower mold, you just have to have a shower. So I’ve prepared a couple photos and I’m going to try to screen share again. Hopefully this goes through this time; I’ll ask you to verify if you see it on the screen here. Can you see that?

Mark: There it is.

David: O.K., excellent, so that’s our cover page. So shower mold. I want to look at some of the myths about it and the facts about shower mold and then at the end I’d like to go through what you can do about it to fix the problem. Let’s get right into it. Showers are gross, they’re dirty, there’s a lot of standing water in them and so they’re a perfect breeding ground for mold growth. So here we see a photo of a pretty standard, tile shower. Obviously this one’s had a significant amount of water leakage over the pan, you can see in the foreground there, couple tiles have been removed and you can see that there’s nothing left of the backing board at all. What we have here is a moldy shower. Now I’m going to differentiate between the shower mold that you can see and the shower mold that you can’t see. If you’re looking at the surface of the shower, you’re standing in the shower and you’re looking down and you see black you’re probably looking at surface growth of mold and it’s taking root in porous surfaces so one of the things about mold is that it like to set up in porous surfaces, it really likes organic material, it really likes drywall, it really likes anything it can bite into and take root. So here in this case we see it around the bottom edge and it’s probably because we’ve got some silicon, there’s silicon caulking right around bottom edge of the pan and the mold has taken root in there. We’ve even got some black fuzzy stuff on the left hand side so this is obviously a pretty significant problem. In this case the shower was actually being torn out and rebuilt due to the moisture problems. But if you have a fairly standard shower, it’s not uncommon to get this kind of growth and it’s not necessarily a reason to panic.

So we’re looking at the edge of the shower here. We can see that the caulking has started to peel up and we’ve got some growth occurring at the edge, the inside corner, so the first thing we can do to make sure we don’t get shower mold growth is to scrub it down and dry it out after you shower. Sometimes you’ll see a squeegee or one of those windshield wiper blades inside the shower where you can wipe it down afterwards. The dryer you can keep the shower the less chance you have of growing mold in it. Second thing you can do is you should be resealing your shower periodically. This is one of the biggest myths about showers is that you don’t have to reseal them. Now there is two ways you should seal your shower, you should seal the corners with silicon and around the base of your pan and around doors, with a quality caulking, here’s one that comes to mind, GE makes it, I believe it’s called tub and tile, something like that, it’s a caulking that you can go around the edges with because mold will grow on the caulking and it’s time to replace it and that’s just typical for a shower.

Second thing you should do, is you should is seal up the actual grout and you can actually get a grout sealing product as grout is quite porous and eventually water will get behind as it passes through the grout and into the backing boards. So that is our non-visible mold. That’s what’s actually growing behind tiles and once you reach that point, you may have to demolish the shower if it gets bad enough.

Here we’ve got a real source of potential mold. This is a bad idea, Mark. I don’t know if we’ve talked about this before in our discussions but windows in showers are never a good idea. They don’t really work, they’re actually allowed by the BC Building Code but you know they’re kind of desirable because they let a lot of natural light into the bathroom but it’s not a good idea to put it in the shower. You should actually put it in a wall somewhere instead. Here you can see that we have a lot of growth of mold around the cold window, right, so we talked last week about mold in windows. What’s happening here is that mold is growing on the cold part of the window, it stays wet a considerable amount of time after you take a shower what also happens here is that the water actually leaks into the wall through the top of the tiles and if you look at the edge of the tiles, that sort of edge closest to you, you can see gaps and cracks in the grout so water is actually leaking behind this wall and this wall had a huge amount of moisture below inside the backing boards so that’s when you really get extreme cases.
If you look here, you really want to make sure that there’s no holes in your tiles, there’s no cracks in your tiles. This is a foreclosure home from Port Coquitlam and we can see that the owners have kicked a hole through this side of the wall and they have solved it by putting duct tape and some garbage bags over top of it. So it’s not really a proper seal and of course this is a terrific way to introduce water in behind the wall cavity. This one was actually was ending up in the kitchen, there was a huge leak that went downstairs to the kitchen below and caused enormous amount of damage. It cost thousands of dollars to repair.
So our next photo we’re showing some moisture readings around a shower, so one of the things that happen, when showers leaks or when you have cracks or gaps around the shower, water can actually get into the drywall and travel down the wall. In this case you can see this is a toilet valve right next to that, it’s about six feet away from the shower and we still have heightened readings as the water travels through the wall so be very careful to always keep your shower curtain, that would be probably the number one thing. This is the same shower here, this is actually a real poor shower design, it doesn’t have a lot of mold in it but we actually found that it was leaking into the walls and there was hidden mold in this one.

Last thing I want to talk about is how to minimize surface growth is to run your bathroom fans so we were talking about it last week, how to reduce mold in your home. The same applies here. If you’ve got a shower and you keep getting mold growth, you need to be running your bathroom fan. Your bathroom fan exhausts the wet air from the house and introduces dry air into the house through the ventilation so run your bathroom fans as much as you possibly can and if you keep your shower clean, dry, and you run your bathroom fan and you’re resealing it on a regular basis, you shouldn’t be having a huge amount of trouble with mold in showers.

Here you can see, this is a moisture meter. This is one of the tools we can use to actually read behind the tiles, that’s actually giving us a pretty high reading. This is the same shower and of course this is how we can tell if there is any damage.

And this is a picture of how to clean your shower. I actually jsut pulled a stock photo of it. What we’re looking at is, you know, clean your shower, shower mold is not really a health hazard. We can certainly test it and check to see if there is an issue with the shower but you want to keep it clean and dry and there are products you can buy from the hardware store, one comes to mind, Microban, there’s another one called Moldex, there’s actually a couple of different products you can buy at the hardware store that will not only remove the mold but will actually leave a layer that will prevent future regrowth of the mold, so it leaves a product on the surface of the tiles.

So basically to recap, you want to keep it clean, dry, well ventilated and well-sealed. And if you follow those corrections you’ll have, you won’t have shower mold growths. Hope that helped out.

Mark: So one thing I had a question about was, what happens, is all mold visible? Can you see all the different kinds of mold or it looks clean but there’s actually mold on the surface?

David: Excellent question Mark. I think we were talking about that a couple hangouts ago about what mold looks like. Mold can look really scary or it looks like nothing and the only way to tell if you have mold on the surface is to test it. If you don’t know if you have mold, or you think you might have mold, you can smell it, something is off, you usually get that sixth sense where you may want to look into this problem, call us and we’ll come out, we’ll sample it and we’ll check to see if you have an issue.

Mark: That’s great David. So, David Fairbairn of Fairbairn and Fairbairn Environmental, they’re going to have a new website or a subset of their website. David’s been cited in the 24 Hour Magazine and on Global TV about mold. He’s a mold expert and so he’s the guy to call if you’ve got any problems. Come to Fairbairn or give him a call 604-395-2795. Thanks David.

David: Thanks Mark, talk to you again.

About the Author DavidFairbairn

Author David Fairbairn is a certified, licensed home inspector serving Vancouver and the Lower Mainland. He has been featured in the media and has contributed to "24" Newspaper, and Global TV. He has spent years working with residential and commercial building projects, and holds a Power Engineering License in BC. Why not give him a call for your next Home Inspection? Call 604 395-2795 or email today!

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