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[d conover]

I just bought insulated pex from z supply and it looks  good.

I made the mistake of only putting a 4" schedule 40 pipe in the floor of my shop. I need an ingenious way of connecting the corragated underground pipe to the 4 " schedule 40. The corrugated is about 4 1/2".
Jeff at
Z Supply sent me a piece of large heat shrink to go over the connection, but I am wondering if I need to do more.  The connection will end up being about a foot down.  I am thinking about putting it in a meter box just so I can see it instead of it being buried.
Thanks

[HandyMark]

I have purchased couplings to go from corrugated to thin wall pvc. If you can not find one to go directly to sch 40 you could surely go to thin then to sch 40. If I am understanding your situation right you could glue all the pvc then use the heat shrink over the black corrugated coupling since they don't glue.

[RSI]

I have purchased couplings to go from corrugated to thin wall pvc. If you can not find one to go directly to sch 40 you could surely go to thin then to sch 40. If I am understanding your situation right you could glue all the pvc then use the heat shrink over the black corrugated coupling since they don't glue.

Are those couplings the ones that kind of snap on the corrugated tube? The ones like that I have seen make it harder to get a water tight seal. Also, the corrugated tube that Z supply uses isn't the same shape as normal drain tile and they might not even fit.

It might be work a try though to see if it does make it a stiffer joint and if it won't interfere with the heat shrink.

[d conover]

The corrugated to smooth pipe adapters I have seen is for guttering etc. where I don't think it matters if it leaks. There may be better ones.


As of now I am thinking about siliconing up the ends of the pipes, using the heat shrink and putting a Fernco fitting over the whole mess. 

[HandyMark]

Are those couplings the ones that kind of snap on the corrugated tube? The ones like that I have seen make it harder to get a water tight seal. Also, the corrugated tube that Z supply uses isn't the same shape as normal drain tile and they might not even fit.

It might be work a try though to see if it does make it a stiffer joint and if it won't interfere with the heat shrink.
[/quote]

Yes. The snap on black couplings they sell with the other corrugated is what I was picturing. I am not familiar with the Z supply. I was picturing the regular drain stuff held together with the reducing coupling then wrapped in the heat shrink to seal it all up tight. That is the only thing I could picture without having my hands on the parts.

Will the PVC fit inside the corrugated? I'm wondering if they could overlap then use the heat shrink over the joint. Seems like that would make it pretty stiff. If there is any gap at all between the two pipes some spray foam or silicone would keep the joint together nicely.

[RSI]

Are those couplings the ones that kind of snap on the corrugated tube? The ones like that I have seen make it harder to get a water tight seal. Also, the corrugated tube that Z supply uses isn't the same shape as normal drain tile and they might not even fit.

It might be work a try though to see if it does make it a stiffer joint and if it won't interfere with the heat shrink.

Yes. The snap on black couplings they sell with the other corrugated is what I was picturing. I am not familiar with the Z supply. I was picturing the regular drain stuff held together with the reducing coupling then wrapped in the heat shrink to seal it all up tight. That is the only thing I could picture without having my hands on the parts.

Will the PVC fit inside the corrugated? I'm wondering if they could overlap then use the heat shrink over the joint. Seems like that would make it pretty stiff. If there is any gap at all between the two pipes some spray foam or silicone would keep the joint together nicely.
[/quote]

Both the corrugated and pvc pipe are 4" ID so can't slide one in the other.

It might be worth trying one of those snap on couplings just to see if it stiffens up the splice but I have a feeling it will be worse than without it there. I think it would mainly be needed to help keep everything lined up.

I think the Fernco fitting would work ok. Is the heat shrink big enough to go over it?

[d conover]

The fernco won't go over everything like I hoped.   I went ahead and bought a corrugated connector and I think it will work.  I tried it in a scrap piece of corrugated pipe and I ended up having to cut it off, it really sticks in there and it does strengthen the connection. 
 
So right now the plan is: silicone the connector to the schedule 40 and corrugated pipe, use water proof tape, use the heat shrink tubing. wrap in more water proof tape, and pray...

I was going to get a water meter box and put the connection in it  if I ever had to work on it, but my brother in law thought that was a bad idea

[HandyMark]

Throw a chunk of metal in the hole so you can find the joint with a metal detector if you ever suspect a problem and need to dig it up.

[RSI]

Are you using the inside out outside type coupler? I was looking at the ones that go inside at the store a couple days ago and I think it would work pretty good. Won't make a water tight seal but the heatshrink should take care of that.

[HandyMark]

Are you using the inside out outside type coupler? I was looking at the ones that go inside at the store a couple days ago and I think it would work pretty good. Won't make a water tight seal but the heatshrink should take care of that.

I have never seen one like that but it sounds like a good solution to his issue. Where are these available?

[d conover]

Here is what I did, if it leaks I quit.
I used a corrugated to smooth pipe coupler and siliconed it in.  I wrapped that with expensive self sealing silicone tape. I applied the heat shring tubing, I wrapped it with more silicone tape.  Then I split a piece of 6" sewer and drain, slid it over the coupling and put a whole can of great stuff foam in it. (I thought about the sewer and drain pipe afterwards or I would have already had it on there)