Hi all,I have the stains you can see in this pics: https://ift.tt/2zkFGBa stains were caused by my bike's tires (I am 99% sure because you can see the tire tread marks in the stain).I have tried scraping hard with normal floor cleaning products to no avail. When I used a metal sponge, it left visible scraps on the surface. I am not sure what floor type this is, my guess is polished concrete?I am in a country where I don't speak the local language very well, otherwise I would just drop by a local home improvement store and ask for help. Also, some googling has given me a few forum posts but mostly dead links to products etc. via /r/DIY https://ift.tt/2Dk7wSB
