cast iron drain

What can i use to cut out some bad drain pipe i have only a very small crawl space

The easiest way to cut CI is with a soil pipe cutter aka snap cutter. The biggest problem in a crawlspace is to make sure it doesn't fall on you. Also, the cutter is also heavy and you need enough room to wrap the chain around it. Once you wrestle it into place and attach it, it takes all of about a minute to actually break the pipe. You can rent them at most tool rental places including HD.

You can get a close corner soil snapper that works great.H.D. has them at tool rental for about $8-9 a day. Make sure it's cast and not galvanized.

Cast Iron Drains

OK thanks to your help i have the bad pipes, cast and galvenized. removed
now can i replace it with PVC if so is there a special grade that i need to use.
Thank you for your time.oh the sizes are 2in galv.pipe into a cast 'y' at one end i connect to 2in galv. pipe then to a y that goes to a vent then down to a cast tee that has a 3 and 1/8 collar on it i hope i gave you enough info i hope i started something i can finish.. Again thank you very much for the help

Schedule 40 DVW. Make sure to use both the primer and the cement. Many inspectors like to see the purple, so pick that type primer/cleaner. The stuff stains, and can be a pain to get off, so watch where it drips. It will also melt holes in some foam and plastics (I know because I dripped some on a tileable foam curb - ate a hole in it!). While the cast stuff was stiff enough to not need that many supports, you'll want to provide some for pvc, depending on the length of the runs.

clogged main

CAN YOU HELP ME OUT WITH SOME TIPS ON CLEARING A MAIN DRAIN half
of my house is fine. The other side the laundry room and the toilet back up into the shower. Thank you for your time..........

My suggestion would be to call a plumber.