Failed Cast iron drain lines

I need general guidance on replacing my entire waste drain system. House is ~40 yrs old, slab on sand in S. Florida, average size 3bed 2 bath. The drain lines under the house appear to be cast iron. We had a break under the kitchen cut out and patched. At that time I noted that there wasn't a really good slope, now the bathroom drain is not working. I'm convinced I will have to bite the bullet and replace all of the drain pipes under the house. I will hire a professional but I really need to be knowledgeable on the subject to prevent typical short cuts.
Will I have to cut troughs across my entire house?
Is there a way to replace or add an alternate set up drain lines from outside the house?
What kind of cost do you think this will be $5k, $10k???

Different areas of the country have different rates and there is no way without us being there to see what is involved to price it...you should get a minimum of 3 estimates....

repipe

Show the job to five plumbers and you might get five different opinion as to how to do the job, and that would mean five entirely different prices. I cannot believe you have a cast iron system that has completely failed in that short a time. But only a video camera inspection, with a recorded tape or DVD, can answer that question. Without that inspection, which will also tell you where the pipes are located under the floor, there is no way to even tell you what will have to be done, or if there are alternate ways to do it.

do what HJ stated ....

hj said:

Show the job to five plumbers and you might get five different opinion as to how to do the job, and that would mean five entirely different prices. I cannot believe you have a cast iron system that has completely failed in that short a time. But only a video camera inspection, with a recorded tape or DVD, can answer that question. Without that inspection, which will also tell you where the pipes are located under the floor, there is no way to even tell you what will have to be done, or if there are alternate ways to do it.

Click to expand...

I doubt that the whole system is rotted away either...

do the camera thing and be sure , thier is no reason to
change any of that unless you are %100 sure it is bad..