how do i replace a drain stack?

Question

i have old cast iron

Answer 1

There are several ways to replace an old cast iron drain stack.

Use a saws-all with a metal cutting blade. Have a helper standing by with wedges to place in the cut so it will not fall on the blade. Be prepared to sacrifice several blades. Once the stack is cut through, beat on it with a sledge hammer, while using a 2X4 to lever it out. Be sure to wear goggles, a heavy coat and gloves,

Just use the hammer method. Not nearly as neat, but effective. If you are careful, you can chip away the pipe in a circle and lever it out with a 2 X 4.

Rent a large abrasive saw, and just cut the pipe in two places.90% of the way through . Use your 2X4 and hammer.

The other pipes shold slide down the chase. As you replace it with sections of PVC, remember to go up on the roof and re seal the roof vent flashing.

Answer 2

You can rent cast iron snappers. They come in manual, hydraulic and ratchet types. Use a No-hub coupling (made for transition from cast to PVC) to attach the new line to the old. You can get these at Home Centers. Wear safety glasses.

Answer 3

need more info, why, how much, are the walls open for easy access? are you just replacing the part that goes through the roof? come on, work with us.