Wondering if anyone has any info on this. I own a house that is just over 1 year old. I noticed mold growing on the baseboards in 2 different places where I have vinyl flooring. I cleaned the areas and it grew back with no visible source of moisture. The house is very clean so it is not a simple cleaning issue. I pointed this out during my 1 year walk through. The builder removed the baseboard and made sure there were no issues withing the walls. The problem areas are not close to plumbing. Then I noticed some purple spots appearing in various areas of the floor. They do not clean off. A cousin of mine looked at them and though they had seen a show about mold under vinyl flooring that is direct on concrete. The builder followed up but claimed they never heard of such a thing. I figured someone on the Net must know.