I have an attachment on the side of my house, basically an enclosed porch but could also be a mudroom. One of the doors leads to a deck where the prior owners let the gutter downspout fall out of place, which let water collect on the deck and get into this small room. I'm wondering if the floor is still good (just stained) or rotting. I was planning on finishing the room which includes tiling the floor. Do I need to replace the wood prior to doing this?