I put crushed stone down about 10 years ago. After a while I had weeds growing up through the stone. So last summer I dug out 1/2 my kennel(about 8" deep) I put landscaping mesh down. I dug two holes and put drainage tubes in at the lowest spot. I poured a 3-4" slab of concrete on top of that. Then filled it back in with new crushed stone. This spring I plan to do the other half of the kennel but I am not looking forward to it as it is a lot of work lol