Connecting drain line to septic tank?
sleddriver
| Posted in Construction Techniques on
I’ve installed a new 4″ sch40 line between the fiberglass septic tank outlet and spliced it in further down to the existing line.
This tank is a 1000 ga fiberglass unit installed in 1981. They broke off parts of the lower outlet lip. The drain line wasn’t even connected, it just lay there below the outlet. I know . . it sounds nuts. But that’s what I found when I dug it up.
I’ve reinforced the tank outlet lip with a few layers of fiberglass & resin, which worked well. The OD of the outlet is ~ 4-1/2″.
Question is: What’s the best way to connect the new 4″ line to the septic outlet?
Replies
Looks like you have a pipe extension coming out of the tank.
If 1981, it should be to some certain pipe size but Schedule 40 is the largest to my recollection. (a little larger than SDR 35 and SD pipe If memory serves me correctly)
If you can get a fernco around it (rubber connector) it will likely outlast you.
If you are concerned with just a fernco, pack it in cement around the fernco and you are done.
I picked up a couple of fernco's, will see which one fits better. I also dropped by a septic supply house to see what they had. Found an interesting filter "T" that that goes inside the tank. Not sure such a thing can be retro'd to my old tank though. I decided to get out the fiberglass & resin and wet up some cloth to support the outlet. Then I inserted a piece of 4" thin-wall inside the tank outlet, set the angle down a bit, and glass'd it together. Tested it today after it hardened and it reinforced the weak joint nicely. I may not need the fernco.I'm curious, how would you go about packing cement around the fernco? I assume you mean on the outside of it. Just cover it on all sides with cement?Thanks for the reply.
Here's a photo of the pipe glass'd into the tank:
quality work for a sh%t job
I've been down in the hole enough on this project. Glad to climb out, fill it in and be done with it.
Sorry sleddriver
was away for the holiday.
Yes, so long as you have firm ground below, just pack cement around 360 degrees around the fittings. You can put some 3/4" clean stone under first to fill the gap as you dont want a huge mass of cement there to weigh the joint down.
Sounds like the fiberglass is working great though so you dont need to re-create the wheel if it is all sound. Still perhaps backfill with some gravel or clean sandy soils to keep any undue stress on the joints.
Yes, for 4" sch 40 has the thickess wall, then SDR 35, then Sewer and Drain. The SDR 35 and the SD have the same OD and can use the same fittings. IIRC sch 40 is slight larger in OD, but I am not sure..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.