I put in a new/used kitchen sink in the house I ren, since there's no dishwasher and the double basins made more sense. Problem now is with the disposal, the sink outlet is about 1/2" lower than where the old steel pipe enters the wall. I opened the wall up to get a look see and the pipe doesn't seem to be strapped anywhere I could see and the vent, although going up from that five pound tee, has to go around the window that is about three feet above. I want to cut the pipe about 2" below the tee so I can put in a fernco san. tee, (all rubber tee with pipe clamps), but I'm not sure what will effectively cut through that heavy steel pipe without starting a fire, plus, I don't know if the pipe below the tee is secured or supported and worried it could fall down into the wall or down into that nasty old crawl space in this 1940 bilt old house!!! Any knowledgeable HELLLLPPPP??? out there. I don't want this to end up costing more than the monthly rent!!!