I need to replace a section of my main drain (4" PVC) between point A and point D as indicated below.



The line makes a 90 degree turn by using two 45 degree elbows to avoid a tree north of A. The distance between the two 45 elbows (points B and C) is 14 feet, so it's quite long.

There is also an elevation difference of 6 to 7 inches between point B and C. Where as the lines upstream of B, and downstream of C is fairly flat at a typical 1/4" per foot.

In order to make this elevation transition of 6-7" between points B and C, I think I can roll the first 45 elbow at B down a little, and roll the second 45 elbow at point C up a little, is this correct? Any advice how much I roll it? Is there some way to calculate it or just "eye ball" it?

Or should I just connect them with no rolling at all and let the PVC flexs to where I need it?



Edited 1 times.

roll them 1/2 a hair by eye

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Half a hair? LOL

What color hair? We used to say red hairs were the finest and brunettes the biggest. But, as soon as you roll the upper 45 down, there is no way to roll the lover one and still make a 90 degree turn. I would use a 60 (1.6 bend) at the top and a 45 at the bottom with a 45 degree slope between them, or vice versa depending on whether you need "travel" between them.

sum,

seriously

'roll' them juuust a touch and you will 'find' 6" over a 14' span



hj,

you are technically correct, but, sum has 14' to cheat

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 1 times.

Haven't you heard, "cheaters never win"?

Sum, 1/4" per foot over 14' is 3.5", so you're only dropping an extra 2.5"-3.5".

in that case may be I should just cement the joint straight without any rolling and just use the PVC's only flex to get me the correct heights? Or like Bernabeu suggested roll it a hair?

? you 'could' add a 45 + street 45 in the middle of the offset to get the 'drop' ?


? why bother ?


? are you done yet ?

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

no not done. Rained every day and the trench got filled up partly with dirt washed back in.

I finally was able to look at upstream cleanout as it exits the house.



As suspected, that downstream joint of the cleanout was not cemented. Once I made the cut it just came loose.

It was quite a bit of pain to remove the joint upstream of it, as it also was not cemented but it was pushed tight together. I had to cut it.



I also replaced the downstream belly, that was a run about 16' long. So I have the upstream pipe at the correct elevation and the downstream pipe slightly lower, without any belly. Right now they are still 6 feet apart but the slope is perfect.





All I need now is to connect the two with a 45. I still need to put in a clean out where it exits the house.

My question now is should I repair the foundation wall hole? It was opened I guess in 2008 when they did the repipe to connect to sewer and they just buried the hole with dirt. I could fill it back with dirt since it's below grade but I wonder if I should repair this wall some.

slip a pipe sleeve over the exiting pipe

fill the gap with expanding foam

mix and pour concrete as required

AFTER AFTER AFTER

you complete and test the work

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Bernabeu, the reason I did not finish connecting the pipe is because of the foundation wall.

The 4" comes out of that hole, which I cemented a short piece of pipe and terminated with a rubber cap for now, will have a two way cleanout and riser attached to it, then a 45 elbow, then a piece of pipe to meet the downstream pipe.

Once I put the CO and riser in place and connect the pipes, I will have no easy access to the hole to finish the repair of the wall. The CO riser will be in my way in the front, and the new pipe will be in the trench and every time I step into the trench I have to avoid stepping on the pipe as the trench is quite narrow.

That's why I am hoping to make the wall repair first, then connect the pipes after.

sleeve now

pour cement after

just in case

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638