Hi, I live in the northeast, well known for its heavy snowfall in the winter. Where I live, for the past few days, it has been raining heavily during the daytime and stopped at night. This has collected in various ducts and pipes meant to remove the water from the roof. At night, when the temperature drops below 32ºF or 0ºC, this still water freezes, blocking the pipe. One pipe in question is in the shape of an uppercase letter "L", where the short branch is perpendicular to the surface of the earth and the long branch is parallel to the ground, but underneath it by a few inches. I suspect that it is frozen along the pipe for a few inches under the ground. The whole vertical section is a solid block of ice. This is causing a backup along the pipe. It is supposed to snow tonight. How can i clear this pipe before then, and keep it cleared throughout the night? I know that salt melts ice by lowering the temperature at which salt water freezes. But this is a very slow process and to melt about a solid gallon of ice will not happen before tonight. It also, most definitely, will not be able to keep the pipe clear and flowing throughout the night. Is there any way to clear the pipe quickly and then have a slow release or timed release of salt into the pipe using stuff found regularly in a home? Thanks.