We had a cooling tower on our roof which was 38 years old. The I beam showed rust and there were different opinions as to will it fail or not if filled with water. I contacted Mr. Bruce Ensor at BE Structural PC. He advised us not to fill the tower. When the tower was removed to install the new one the steel base was almost totally rusted away. If this tower was filled it most certainly would have collapsed. Thank you Bruce Ensor.