Cast iron drain leak under pier and beam house

[geodepe]

Hello,

My cast iron drain from kitchen seems to have decayed near a joint.

My thought was to use a reciprocating saw or "snap cutter" to make two cuts one foot away from the join on each side. Then I plan on inserting a section of PVC with "fernco rubber coupling" with stainless steel clamps (not sure if shielded is needed).

Is this a good idea?

Also, I was thinking of lifting the cast iron out of the mud and clamping them to the underside of the house with one of those metal straps with holes in them. Is there a risk of breaking some of the other joints?

Alternatively, someone suggested replacing the whole line with PVC.

The image shows the problem. Any suggestions appreciated. Thanks.

[johnjh2o]

You can try to make your repair but my guess is you will find the rest of the line is also bad. It's all the same age. Kitchen lines are the first to go. I would cut it back as far as possible and hope you find some good pipe to connect to.

John

[LiQuId]

I would add that snap cutters usually dont work in this situation as the pipe is too brittle and fragments way to much. If the pipe is to be buried then you need a shielded no hub coupling ( MJ ) otherwise a fernco will work, and it is better to replace the whole line as john has said. its all bad.

it is a slow process but a recip saw with a cast iron blade in it, or a grinder with zip disk would be my advice.

[geodepe]

John/Liquid,

I was afraid that I would have to replace the whole line, but I think you guys are right.

Would you recommend connecting the PVC directly to the cast iron cuts with fernco or is there a way to fit the PVC into a cast iron female joint? or course I would have to figure out how to remove the male portion?
Now that I think about it, that would probably be more of a hassle than just making the cuts?

Thanks for your advice.

[havasu]

Use ABS, not PVC. I'd recommend cutting as much of that rot away, use a couple of Fernco fittings, and fit in a nice long section or two of ABS, and strap it so you continue the correct fall, and call it a day.

[johnjh2o]

Just curious why ABS and not PVC?

John

[havasu]

John, You bring up a great point. I just checked the specs at a manufacturing company for both ABS and PVC and they seem peculiarly similar. In the area I reside and Lake Havasu area, PVC is never used, but it is possible because the PVC will break down in the direct sunlight, unlike ABS. I also do know some of the contractors in the area easily identify waste lines as being black, not white.

With this being said, I will retract my previous statement unless it is prohibited by local code.

[johnjh2o]

There is no reason to retract. As you say they are both very similar. I have used both but the main reason one is usually chosen over the other is by what is most available in a particular area. The biggest problem I had with ABS was trying to remove the black solvent from my hands at the end of the day.

John

[LiQuId]

amen to this ^

[geodepe]

Ok ... thanks for all your help.

Job took less than 2 hours.

I used reciprocating saw with carbide diamond blade.
Saw cut through 2" cast iron pipe like butter.

I pushed aside the old pipe and connected the first PVC with fernco.
Connected remaining PVC and finally last fernco.

I used level to check slope (was barely going down hill ... should be good ... I think).

Finally I installed a support hanger strap.

I used a 500w $10 utility lamp from Lowes. It turns your crawl space into daylight.

I also used a heavy gauge extension cord with 3 way grounded splitter on the end so I could attach the saw and lamp at same time.

I had to cut a hole in one of the crawl space vents to get the pipes under the house.

All in all ... it was easy and it saved me $1600.

Thanks again.