One of the most common places that I find plumbing leaks during home inspections is at the showers. Steel showers always leak, glass doors frequently leak, and tiled shower floors will usually leak if they’re installed wrong. Any time I inspect a home, I do my best to find these leaks. Today I’ll share a few of my methods.
Metal Showers
These old showers look really nasty. All I need to do to make these leak is run the water. They leak at the sides every time! The fix is to replace the shower.

Glass Doors
I’d estimate that about every other glass shower door leaks. To find these leaks, I simply point the shower head at the corner of the wall and door intersection, turn the shower on, and let it go until it leaks. If the door doesn’t leak right away, I leave the shower on for a few minutes, inspect a different room, and come back again. If there is still no leakage, the shower passes. If it leaks, the repair is usually as easy as adding some caulking at the inside of the shower at the intersection between the wall and the base.

While a leaking glass door typically only allows some water to leak on to the bathroom floor, this can eventually lead to major water damage at the sub-floor if the shower base or tub isn’t properly caulked at the floor. The photos below illustrate this quite clearly, I hope. To help prevent damage here, always make sure that the tub or shower is properly caulked at the floor.
Tiled Shower Floors
They look great, but they often leak. These leaks sometimes take a long, long time to manifest themselves because the leaking is often very minor and very slow.
I look for caulked joints in the floor, cracks in the floor, and patching at the ceiling below. I also use a rubber shower dam to fill the shower with about 2″ of water. I leave the water slowly running in the shower and I don’t worry about it overflowing – that’s the beauty of using a dam. I’ve found a lot of leaking showers using this method. The leaks usually take a while to show up on the ceiling below, but it’s dramatic to witness once it happens.
The repair for a leaking shower is to replace it. Caulking any cracked areas in the tile is not an acceptable repair.
Shower Drains
Shower drains occasionally leak at the connection between the drain and the tub or shower. I find these leaks by carefully examining the area below the drain for any drips after I’ve run the water. These repairs are usually quite simple.
Plastic shower drains ocassionally leak, and these leaks are extremely difficult to find during the course of a home inspection. A friend of mine had a big stain on his ceiling below the shower, so we spent a couple hours trying to figure out where the leak was coming from, but we couldn’t make it leak. Two days later, the stain got bigger. It turned out that the drain was leaking only when he was actually standing in the shower, which caused the shower floor to bow just enough to make the drain connection leak. I’ve never found a leak like this during the course of a home inspection!
Reuben Saltzman, Structure Tech Home Inspections - Email - Home Inspector Saint Paul
Nice post and I certainly appreciate the photos and info!
your friend in Charlottesville Virginia!
Hey I bought one of those shower dams a while back. To be honest I've used it once or twice but perhaps I should use it on a regular basis.
Thanks Charles
Vince - I'll sometimes let the water run on low for an hour or two. Sometimes it will take that long for leaks to manifest themself. Keep using the dam - you'll start finding leaks!
Reuben, To play devils advocate here, isn't leaving the water on for hours an unrealistic test? Also damming the water in the shower, when would the shower fill up with 2 inched of water?
I admire your innovative methods, but wonder are they finding leaks or creating them.
James - great question! It typically won't take hours, but it can. The way I see it, if a shower shows a leak after an hour or two, it was really leaking the whole time - just very slowly. Rather than having a buyer find out about a shower leak four years from now after their sub-floor is rotted out, I find out about the leak right away.
I was going to include a youtube video of a rotted subfloor in a tiled shower, but I couldn't figure out how to embed it in my post. I think I need to pay for a premium membership to be able to do that. Here's the link, it's only about a 6 second clip http://www.youtube.com/watch?v=uXUgNxEcIEY
About damming the shower: most tiled showers are quite a bit lower in the middle than they are on the sides, so even if there's 2" of water in the middle, there might only be 1/2" of water at the sides. A properly installed membrane will go up several inches on the sides - much higher than I ever get the water.
If I find a leak using this method, it's a leak that was already there. Any plumber will agree that a properly functioning shower will pass this test, and about 90% of the showers that I test don't leak.
Thanks for the explanation and I agree with you. I might just have to buy one of those shower dams:)
Rueben: Great techniques! I also am very talented at causing leaks to show and frequently have to explain to plumbers what is going on. A picture is worth 1,000,000 words.
The good thing about using a dam is that it allows the drain to be tested at the same time. Sometimes the leak is at the drainpipe connection as you mentioned. Thanks for the insight!
Jim - you said it. No one can argue with you when you have a photo proving it, and the buyers saw it happen. It's a lot better than saying "recommend further evaluation by..."
Glen - great point. Thanks for reading.
I like the water leaking out of the light fixture. I've been fortunate that I haven't found that type of leak yet.
I see a lot of leaking on cielings but most seems to come from the toilets.
Russel - funny, I've actually seen water leaking from light in two different houses that I've lived in, along with several inspections! At my own house, one was a leaking washing machine and another was a burst water pipe.
Gene - yes, plenty at toilets too!