Originally Posted by SuzyHomemaker
I have the same thing on our kitchen floor linoleum. And it is growing. I believe it is a mold underneath. It was by our window, so I suspect there was a leak of some kind. We are ripping up our linoleum, fixing our window, bleaching the spot under the linoleum where the mold must have been growing and laying new floor. Not good news, but necessary.
So what type of underlayment was there, and did you follow the water trail to the window area? How did you fix the window, did you do a water/hose test?