Frederick M. Hueston, PhD

I was enjoying my breakfast at the local greasy spoon and listening to all the old men tell the same basic it-was –better- back-then story over and over again. I kind of tuned them out as I downed all my flapjacks.  Just as I took my last bite and asked for the check, my phone rang.

I hastily swallowed and said,  “Stone Detective here. ”

The voice on the other end had a really deep voice. He kind of sounded like Lurch from The Adams Family – or was it The Munsters? Anyway he told me that he had a white marble shower that was turning dark from the bottom up. I asked him how long this was going on and how old the shower was. He said he had no idea since he just bought the house and moved in last week. He asked if I could come take a look. I asked for the address and it was only ten minutes away. Guess I’ll have to postpone my fishing trip this morning and actually do some work!

I arrived at “Lurch’s” home and it was a house right out of a horror movie. It was an old Victorian that was in bad need of a paint job. The wood siding was grey and weathered, and I couldn’t even tell what color it used to be. The oak trees in the front of the house were old and covered with Spanish moss, adding to the spooky effect.

 I parked the Woody in the drive and went to the front door. The door had a large knocker that reminded me of the knocker in the movie Scrooged

I expected that door knocker come to life, so I reluctantly grabbed it and quickly knocked three times. 

I waited what seemed like several minutes,  when I heard someone walking toward the door. The door slowly opened and there stood Lurch. This man had to be at least 6 foot 4 and was wearing an Honest-to-Pete leisure suit! 

If it wasn’t for his shoulder length hair I would have sworn Lurch was reborn in a bad ‘70s sit-com.

He asked me to come in and to follow him.  The inside of the house looked like it had been remodeled. It had fresh paint and new furniture. He led me up the stairs and was droning on in his bass voice about the shower and the discoloration. 

I followed him into the master bath and noticed that it too had been remodeled. I asked him if he knew when the remodeling had been done.

“Certainly,” he rumbled.  “The previous owners claimed the entire house was redone about a year ago.”

I opened the shower door, and sure enough the entire shower bottom was dark. The discoloration continued up the walls about two feet, and I’d seen it before – a condition we call rising damp. I took out my moisture meter to make sure it was in fact moisture. No surprise, the meter pegged in all the dark spots. It was clear what was going on.

Shower failures are probably the number one stone installation failure I have seen over the years. Many times it’s improper slope, poor installation or clogged weep holes.  

Luckily, this was an easy fix and I knew right away what had caused all this moisture. But before I get to that, let me give you some interesting facts about the average shower.  

A friend of mine, Don Halverson, did a study a number of years ago and calculated how much water the average shower uses in a year. Care to take a guess? The wettest state has an average rainfall of over 105 inches per year. The average shower has about 1,935 inches of rain a year. That’s a lot of water. So we can assume that your shower is most likely the rainiest place on earth!

 Now, the number one problem I see with showers is that the weep holes become blocked over time. Soap scum, skin cells and another yucky matter will clog them. When this happens, water backs up in the shower pan and starts to climb up the walls. 

The fix is easy. I took the screen off of Lurches shower drain and took a little tool I crafted which is basically an awl with a bend in it. I placed it down the drain and found that the weep holes were indeed clogged. I opened them up and told Lurch that it would take several months for the shower to dry out. 

Now with that said, I have seen installations where the installer plugged the weep holes with setting mortar. 

If this is the case there is not much that can be done other than to tear out the shower. I told Lurch that he should have the weep holes unclogged from time to time and he should be good to go. Another case solved – and I actually repaired something this time!

The Stone Detective is a fictional character created by Fred Hueston, written to be entertaining and educational. He has written over 33 books on stone and tile installations, fabrication and restoration and also serves as an expert for many legal cases across the world. You can send any email comments to him at .