Any plumbers out there? 50 year old house with cracked drain pipe somewhere under it

Kyle_in_Tex · Jul 13, 2019

My buddy at work is about to pull his hair out. His kitchen sink drain pipe started leaking in the wall behind the sink as it's going into the slab. He actually tore into the wall, and then busted a 20" square hole through the slab to try and see what's up. Apparently, the rusted out drain goes further than he can see.

The first plumber came and gave him a rough estimate. $5000 to dig the first 3 x 3 x 5' up underneath his home. If they have to dig further, it's $500 per foot, which means he could be strapped with up to $30,000 bill to replace the cast iron drains under his slab. He knows there are junctions from each bathroom, and the utility room.

Is there an easy way to dig this? I was thinking of using some type of auger on a drill to help loosen it up.

Is there an easy way to put the dirt back and pack it? I looked at a Youtube video where a guy was making "mud balls" and chunking them into place.

Buyers beware, if you buy an older house, get the drains checked with a bore scope.

RoyKing · Jul 13, 2019

Terrible job, he has no idea what he will find. Although I seldom see cast iron rust away in the ground, sometimes where they hit the slab. I would buy one those rubber sleeves and patch into rusted cast iron and bring back up via Pvc. Who cares if some water leaks under the slab on a drain.y

Kyle_in_Tex · Jul 14, 2019

thanks Roy.

jaxs · Jul 14, 2019

What make's him think pipe need's replacement farther in than what is now accessible? Are yall thinking of tunneling beneath to replace pipe diy? Any where in Tx other than Panhandle,a basin and pump beneath sink and pumping waste overhead into a stack is another solution.

Kyle_in_Tex · Jul 14, 2019

He's gathering opinions and options, to be weighed.

He doesn't really have the money to be doing this sort of thing. Most people can't pull $5000 out of their wallets. Neither can I right now. Having to pay back some medical bills, but thankful I have my health and stamina back.

Maybe I should help him dig, to get some more stamina back.

RNeumann · Jul 14, 2019

How to Repair a Sewer Pipe Under a Concrete Slab | This Old House - YouTube

The $500 a foot quote was from a guy who didn’t want the job.

The steel pipe typically wasn’t used under the slab so thinking everything is rotten is unlikely. Under the slab should be cast iron. Typically the cast iron doesn’t rot unless it’s exposed to some type of chemical that eats it. Maybe the old owners were putting something (maybe a cleaner) down that drain.

The video above is a worst case! Odds are it won’t get to that point.

jaxs · Jul 14, 2019

Ok,I'll assume this isn't on an outside wall with a main line in yard 10'-15' away. Rent a small electric chip hammer and spade to fit it. When tunnel reaches point where there's no room for shovel,go at it with the chip hammer. Use an intrenching tool to scoop up loose dirt and put it in sack or bucket to be pulled out and dumped. The same chip hammer with bell head can be used to pack dirt and mud balls as tunnel is filled. You can't fit all the dirt back.

ultrarunner · Jul 14, 2019

RNeumann said:
How to Repair a Sewer Pipe Under a Concrete Slab | This Old House - YouTube

The $500 a foot quote was from a guy who didn’t want the job.

The steel pipe typically wasn’t used under the slab so thinking everything is rotten is unlikely. Under the slab should be cast iron. Typically the cast iron doesn’t rot unless it’s exposed to some type of chemical that eats it. Maybe the old owners were putting something (maybe a cleaner) down that drain.

The video above is a worst case! Odds are it won’t get to that point.

Not a day goes by without learning something new here.

Thank you for posting!

Kyle_in_Tex · Jul 14, 2019

RNeumann said:
How to Repair a Sewer Pipe Under a Concrete Slab | This Old House - YouTube

The $500 a foot quote was from a guy who didn’t want the job.

The steel pipe typically wasn’t used under the slab so thinking everything is rotten is unlikely. Under the slab should be cast iron. Typically the cast iron doesn’t rot unless it’s exposed to some type of chemical that eats it. Maybe the old owners were putting something (maybe a cleaner) down that drain.

The video above is a worst case! Odds are it won’t get to that point.

The plumber who estimated said that probably 2 reasons for pipe failure. Cleaners used in kitchen area, and the house has settled and has a cracked foundation. There is also a very large 2'+ diameter oak tree very near the area of problems. I told him the tree might have to go. He says is is shade for much of the home and the driveway....So he has some decisions to make.