Rocket, last year I had a 30 X 45 Morton building built. I installed a 16' long drain in the center of the building and had the concrete sloped toward it. I used a 2 X 4 piece of lumber as a guide to make the drain 1 1/2 inches lower than the outside walls. You can barely tell that there is a slope. The good part is that all the melting snow and ice from my truck or tractor run right into the drain then out onto the grass. You can wash the truck, tractor, dog in the middle of the winter and not worry about water freezing up if it was sloped toward the garage door. The bad part, none, other than there is a metal grate in the middle of the floor. And for those who are concerned about running it out onto the grass I have no intentions of dumping oil, grease, radiator fluid, etc. onto my property. The drain was installed only for washing the vehicles and possibly the concrete floor itself.