I built a laundry in part of my garage. For access, I took down part of the wall between the main house and the garage, and then I built a floor about 12" above the cement garage floor, so that the level is the same as the house. Under the floor, I have all the water supply and and drainage plubming. For the mains supply to the washer and dryer, I have an electrical junction box to connect the new outlets to the existing house wire. So, I began to become concerned about flooding from the water supply running down below the built-up floor. So, I changed the juction box to a water proof one. However, I had to open the sided of the box to install the wire strain reliefs, and that makes the box less than waterproof. So, I carefully applied RTV sealant to the strain reliefs and sealed up the wire entry as best as I can. I believe it's pretty safe now. Does anyone else have any opinion on my electrical waterproofing???? BTW, the box is attached to the floor joists on the built-up floor, so it isn't flat on the cememt floor. In other word, water may run off on it, but it will never become submerged, no matter how much flooding I have.