Cutting concrete floor

[kmdigital]

Based on your description, the pipe goes into the basement, and then out under a slab floor. My guess is that it is 4" cast iron. Is this correct?

A couple of questions.
How many toilets on this drain line?
How straight is the pipe? I take it there is a cleanout in the basement, so if you take it out, is the pipe nice and straight under the concrete floor?

If the line is reasonably straight, and there aren't more than 2 toilets on this piep, I would see if you can push a piece of 3" sch 40 plastic pipe through the inside of the 4" pipe out to the outside of the house. Dig down on the outside, cut a section out of the pipe and transition back to the 4" line. Inside the house, cut the cast iron off flush with the wall, and repipe as necessary to connect to the line. It would be best to take 3" all the way to the toilets, but it isn't really necessary if you use a tapered fitting instead of a straight fitting from 4" down to 3".

It might be best to install low flush toilets as well, but probably not necessary. It would be best to make the transition in a vertical section of pipe or fairly steeply sloped horizontal section if possible.

If that isn't possible, I would run a complete new line before digging up that kitchen floor. That is a major undertaking!

It really isn't that hard to dig a hole large enough to get a new pipe through right under the concrete, assuming that the dirt isn't full of rocks or other debris. Knock a hole in the concrete wall, say 6" diameter or 8"x8" (1/2 block) and start digging horizontally with a tile spade. You can strap longer lengths of wood to the spade as you get deeper and just keep going, bringing the dirt back into the basement.

You can also dig in part way from the outside, maybe 4' so you only have to go 8' or so. I've put dug as far as 14'+ under sidwalks and bushes doing this, and it actually works quite well.

Push the new pipe through, make the connections, seal the hole in the foundation, and your done. Much easier and less mess then tearing up your kitchen floor.

[curly]

Originally Posted by MarkV

FrogLick if your soil isn't too rocky you can use a water jet to get under the drive. Basically you glue a jet end onto a stick of PVC, the heads are sold at Home Depot, and a garden hose fitting on the other end of the PVC. Dig a ditch on either side of the drive, turn on the water and push your probe in to cut pull out to wash away the spoils. It is a bit of a mess but it will get you there. One piece of advice, make sure your ditch can drain the water away or you will be up to your knees in muck.

MarkV

Yes, I've done the water jet under a sidewalk...worked like a charm. If you get a PVC a bit larger that the hose nozzel, just stick the hose in the pvc and keep pushing the hose thing though as it bores. Of course I only had 4 ft or so to go...but the concept is still the same.

[mark1]

Ok guys, thanks for all the ideas..I couldn't wait any longer the cellar was getting pretty wet. Had a local plumber come in, he used a diamond blade, and a BIG jackhammer. made a couple look see holes,found the bad areas and replaced the pipes over to the wall stack before it goes out to the septic. It was only 2 inch cast iron.no toilets are connected to it. Just kitchen sinks and washing machine drains.It's now all 2" PVC with 3 cleanout plugs and a extra somekind of vent. I never expected this kind of service from a plumber, 2 guys were here for over 9 hours took a bunch of dirt/sand and 6 bags of morter and concrete. Only chg.1100.00 + tax..I expected 2K or more. I would of had to rent a concrete cutter and a jackhammer, and make a Zillion trips to Home Depot ..