septic pipe replacement

[Kell]

The pipe between my septic tanks has failed. Looking to replace myself using my mini-excavator, but am wondering which specific pipe material should be used to replace existing - I assume some type of PVC. What type of coupling is needed, and what tool would be safest to use to cut the existing steel pipe? Thinking if I use anything that throws a lot of sparks, I will need to force fresh air through the system to remove combustable gases. Thanks in advance.

 

[newhollandnut]

A lot of that depends on what existing pipe you have. If you're just replacing a small piece I would just use sdr-35 pipe and two fern co couplers. Just make sure you bed it good with stone to keep it from settling.

 

[smash59]

sdr 35 or scd 40 pvc either one would work. if you are replacing the pipe into both tanks, a 2 pound hammer will crack the cast iron pipe out. if you are just replacing a section we just use a gas cutoff saw with a metal blade. we have never worried about ventilation with the sparks. usually plenty air with a hole dug open.

 

[Kell]

At most, 10ft of pipe. Yeah, that's basically what I was thinking with the blue pipe and rubber couplers. I believe the existing pipe is 4in steel. For stone, are you talking class 5, or something different?

 

[Brown Swiss]

Better make sure it is legal to do it yourself, my county it all has to be inspected every 3 years and any work done has to be done by a licensed fellow, hope your county has more sense!

 

[Kell]

Crack the actual pipe, or crack the pipe and baffle out of the tanks? Baffles don't appear to need replacing, but that may change once I get the pipe removed.

 

[Kell]

Thanks Brown Swiss!

 

[greg oliver]

Kell, we use schedule 40 - 4 inch PVC on most of the septic systems we do. If you have cast iron I cut it with our chop saw with 14 inch abrasive Wheel. You can uncover your tank and pull the cover if you are worried about fumes. You can purchase Fernco couplings to reconnect pipe they look like a rubber coupling with two hose clamps. In our area if you have the black ABS plastic pipe and need to hook to PVC you must use the Ferco coupling. Remember you need to call before you dig it's the law. Greg

 

[newhollandnut]

Yes 5's would be fine. I prefer 8's they are just a little easier to work with. I'm not sure how familiar you are with pipe or pipe term but "chink" the pipe really good ( lay the shovel with the face vertical against the pipe and use your foot to shove it down this forces the stone under the pipe for support) I would especially "chink" around the couplers and the middle of the pipe

 

[newhollandnut]

http://youtu.be/l1HqP4slNaQ

This might help explain what I am talking about

 

[jdknucklebuster]

(quoted from post at 16:16:29 10/28/15) At most, 10ft of pipe. Yeah, that's basically what I was thinking with the blue pipe and rubber couplers. I believe the existing pipe is 4in steel. For stone, are you talking class 5, or something different?

I replace waste pipe inside and outside house's all the time. Some excavators use sch 35 pipe for sewer pipe prior to the tank underground, but it's a bit shabby. For underground use PVC sch 40 std or foam core or use the greenish PVC called SDR rated for sewer or drain. My advise would be, don't just replace that 10 section, while you have the machine and are digging, replace it clear to the house. The rest of it isn't far behind, and let's roots in at every connection. Cut off the cast at the exit of the house, using the cut off and connection method above and run to the tank. cement any holes at the tank connections to keep roots out.

 

[ohiojim]

i always used sch. 40 PVC

 

[Kell]

Thanks. And nope, I hadn't heard that term used for packing fill before.

 

[ObsoElitist]

I replaced mine with 4 inch PVC. I removed about 3 feet of the old stuff at each end and layed the PVC next to the iron one. Iron pipe cuts fast with a Sawzall with little chance of sparks.
I bought a ditch witch for $30 at an estate sale, useful but if you have a ripper soften the ground first.

 

[Hoenes]

I was told to always pour quick-crete around the hose clamp fittings, because even though they are stainless, they will eventually fail.

 

[jdknucklebuster]

(quoted from post at 07:01:12 10/29/15) I was told to always pour quick-crete around the hose clamp fittings, because even though they are stainless, they will eventually fail.[/
I still stand behind the, if you have the tools on the job do the whole line. The only time I just do a repair, is after I have ran the camera down the line to confirm no low spots holding waste, bad joints, root entry, or cracks in the pipe. And, that would be NEVER in old cast iron. It's bad in the section you have because it's run it's life span. It's done. Unless your planning to move soon, and stick the next person with the problem, do it right.
I don't want to be argumentative on someone else's suggestion, but here the fact on using concrete over a joint. 1) stainless steel band clamps are a code approved plumbing connection, concrete is not. 2) I have dug up plenty to find that when the concrete shrunk back, it left a path for a small root to creep in, grow large, and pop off the concrete. Then poor me, swearing now at the previous repairer, has to hammer off the concrete off to deal with it. In the case above, the joint would not have failed I guess, because the fernco joint would never have not failed. With being a licence plumbing business, we have to do things correctly because we got way to much to do, to do it twice. I highly agree the above that stressed compaction! If everybody laying pipe could have run a camera down a line to see the low spots holding waste from sh*tty workmen ship from no compaction would change their method of installation. Remember, It's a crappy job but some's has to do it. Heck of a retirement job from the nice clean office job I had.