Black Indentations On My Old Hardwood Floors

Dents happen when something heavy or blunt strikes the wood hard such as a baseball or even dishes that are dropped and broken.
Black indentations on my old hardwood floors. I have a polyurethane treated oak hardwood floor which i managed to damage yesterday. Removing dents from hardwood floors is a different process from removing scratches. Many dents can be removed by using a combination of heat and moisture to raise the wood back to its original form. A red oak floor littered with tiny black and gray spots.
Up until recently my eng wood floors looked great with a smooth surface and sat perfectly flat and solid onto of the cement. I rolled a 99 kg treadmill the treadmill has wheels across the floor which left 2 indentation marks in the surface. Like carpet and any other type of flooring you must clean and maintain wood floors to keep them beautiful. Im having an issue with my engineered wood floors which were installed in my condo almost 5 years ago on top of the original cement floors which were already 20 years old.
I recently came across a condition on a hardwood floor i had not seen in my 25 plus years as a consultant. The homeowner told me the black spots appeared soon after the floor was resanded and had become increasingly worse.