Replacing floor of water compartment. What's best to use?

Coachmen, and I guess other manufactures, have one door opening basement compartment where everything is located. Black/gray tank empty, hoses, tank rinse connections, fresh water incoming, outside shower, water filter system, water pump and all of the valves for the rv water system. Even a paper towel rack. They sometimes refer to it as the water works....

I think my problem arose from my wanting to keep the compartment clean and regular washing it out.