A couple of months ago I was contacted through the Active Rain, Contact Form, by a person with a plea for help resolving a question about some staining of the floor around a toilet 
. This person had "Googled" the internet and apparently found me----perhaps because of a blog I had done about stains around toilets. They wanted to know my opinion of the causes of this staining, and they sent me this picture. 
They told me:
"I've had two plumbers here who say that it cannot be water damage."
Here is my response:
"From here:) that looks like classic staining of the backing of the vinyl. Water getting into it somehow----now it is a matter of figuring out how. With a moisture meter one can determine if it is more focused around the base of the toilet or the water shut-off. As this backing stains, it becomes "visible" through the translucent surface of the vinyl."
I also told them:
"Any reputable plumber should know that staining like that is indicative of moisture under the vinyl."
They just updated me on the "third" plumber who "acknowledged there was a leak either at the o-ring or the water line into the bathroom." When they pulled the toilet and pulled up the vinyl around the toilet----water had been leaking at the wax seal and seeping under the vinyl----one of the two likely suspects I had predicted.
It is fun to be accurate---but infinitely more rewarding to be helpful.
Charles Buell
PS, for those of you that are new to my blog (or for some other "unexplained" reason have never noticed)
all pictures and smiley-face inserts (emoticons) (when I use them) have messages that show up when you point at them with your cursor.
* * * * * * * * * * * * * * * * * * * * * * * * *
Click on the Rose 
to check out: AHA!---A Forum of Landmark Proportions---your Group
PS, for those of you that are new to my blog (or for some other "unexplained" reason have never noticed)
all pictures and smiley-face inserts (emoticons) (when I use them) have messages that show up when you point at them with your cursor.
My WORDLESS WEDNESDAY pictures and some selected POEMS & STORIES.
It's amazing that the first 2 plumbers didn't think this was a water leak of some sort.
Very interesting...I have run into a problem like this where I had two bids in a possible problem in a crawl space and both bid came back with no noted problem. When the property was inspected by the buy the inspection was returned with serious problems we could have resolved had the two professionals saw and fixed.
I appreciate people of your caliber who know their business and want to get out good information out so people are not stuck dealing with problems the would very much like to fix and or avoid.
Hope, I agree---you have to wonder what they did think the cause was.
MarQuis---unfortunately an all too familiar story---you call for the "professional" and the professional doesn't see the issue. Still better than calling Mr-fix-it in most cases however.
Charles, we also find lots of staining of vinyl, probably cheap vinyl, where the glue underneath had bled through. The explanation given by the vinyl people is that they made it illegal to put asbestos in vinyl anymore and the asbestos made it stronger. So what was underneath now bleeds through.
Barbara, you are right that some adhesive will bleed through the vinyl and installers have to be careful about this. Most manufacturers only warrant installation over new clean substrates. The main reason that stains of any kind become visible is because modern vinyl floor coverings are "translucent" whereas older floor coverings with more solid material all the way through. Doubtful that it had anything to do with the asbestos content. Some of the newer "retro" floor coverings have gone back to this solid look---called true inlay. You have the same color all the way through instead of layers of translucent colors.
I'm surprised they didn't have insect infestation as a result of this.
Carol, over time----wet wood equals rot and/or bugs.
Truly, the plumbers should have noticed this. I made the same call that you did Charles. I thought it was the wax ring. The plumbers should have been happy to find this problem. Isn't that how they get paid? Plus, I'm sure that a quick trip into the crawlspace and a peek under the insulation around this drain would reveal wet and damaged wood. This is a very simple problem to diagnose. Plus, the moisture meter is a big help too.
Keep up the random acts of kindness.
J Brandon, not just noticed---know what the heck was going on:)
Perhaps the asbestos theory was just to get out of removing the old vinyl when putting down new. They'd say they couldn't take the old up because of asbestos! Then they'd lay a new one on top and the old pattern would show through. Tacky, tacky.
Barbara, usually when they are going to go over the top another flooring they will go over it first with a layer of 1/4" underlayment and then put down the new vinyl----if there are no "height" issues. It usually can be done in less than 3/8".
I have seen enough of this to know that when the vinyl changes, it is usually water penetration. I too think a plumber should know. A plumber should be able to afford a good moisture meter but I have never seen a plumber with one.
I also find it totally amazing that this woman was somehow able to find not one, but two incompetent plumbers in a row. What do they teach those guys?
I have finally noticed that some of the plumbers at least around here now carry moisture meters, and yes, even infrared cameras. But then there are still the guys out there that resist change and new technology.
Steve, for me, with this kind of staining it is only a matter of whether it is past or present. Sometimes they dry out from past leaking and the staining is mostly cosmetic.
Kevin, lots of people see us inspectors as "generalists" and yet in some cases we are more accurate than the profession we would be recommending. Interesting
Charles,
I get these calls from people occasionally as well. Someone just looking for an answer to a problem. I am always happy to help. That is one reason I became a home inspector, to share my knowledge and help people.
James, how it feels is reward enough isn't it?