Removing an Old Tub
Master plumber Rex Cauldwell outlines his technique in this excerpt from his latest book in the For Pros By Pros series: Plumbing
A steel, plastic, or fiberglass tub will lift out easily. Cast iron, on the other hand, is hard and heavy. Unless you have Superman to help you, I advise breaking the cast tub into small sections and removing it that way. Make at least two cuts with a diamond blade on a circular saw. Even then, it will take a lot of muscle to swing the sledge. Wear safety glasses and gloves and protect everything. Warning: The broken shards will be razor sharp.
To remove the old tub, reach in and cut the water and drain lines with a reciprocating saw. Also cut the drain line in the basement. 
Remove a row of tile and the trim from just above the tub, then use a car jack to lift the tub free of its mounting.
Turn the tub to expose its weak side. Protect yourself and the floor (and everything else) from flying shards of broken cast iron. 
Pound the side until it breaks. With the sides gone, move to the front, back, rim, and bottom.
Nothing left to do now except clean up the mess. Bottom line: This is easier said than done.
Demolishing an old cast-iron tub can be quite messy and hazardous. As you smash the tub apart with a sledge hammer, razor-sharp shards of broken metal and dust will fly everywhere. For any demolition, wear appropriate gloves, safety glasses, a long-sleeve shirt, a dust mask, and a hard hat. Be sure to remove anything that could be broken by flying debris.
Rex Cauldwell is a master plumber and electrician. He is the author of Wiring a House, For Pros By Pros: Plumbing, and Inspecting a House, all published by The Taunton Press. Photos by Rex Cauldwell.
