What is best connection of fixtures to main waste line?

[DIY Webber]

Hi first time poster. Building my own home. Thank you for your time.
I have a few questions and will start with this one

What is best (horizontal) connection of fixtures to main waste line?
At a 45 degree angle with just a WYE?
or
At a 90 degree angle with long sweep 90?

I see that most install 90 degree connections, but would it not be best to connect at 45 degrees resulting in less pipe from fixture to main line and at a better angle?

 

[Geofd]

if your asking what fitting to use on your main on its back or on its side picking up a branch.....it would be a wye....if you are making a directional change a long sweep
could be used as long as you have a way snake thru it if needed

 

[DIY Webber]

Thanks for the quick reply Geofd.

What I have is a 4" main line through the crawlspace from septic tank to end of run at utility room and each fixture along the way will connect to one side of the main line or the other.
So..say I have a 2" coming from the washer--down into crawlspace - sweeping 90 from vertical to horizontal Where the horizontal 2" ties to main 4" line, should it tie at 45 degrees or 90 degrees?

It sounds like you are recommending at 45 degrees with a wye? Correct?

 

[Geofd]

a long sweep thru the floor if you can use a dandy cleanout on the vent just above the washing machine so you have direct access for snaking in the crawl space if you have
if you can go straight into the wye without any fittings that's best but your directional changes can be long sweeps or 45...if you have access easily enough use a wye and end
cleanout so you have multiple spots to snake from

 

[Diehard]

I believe SC uses the International Plumbing Code(IPC)
If you don't already have access to it, this site is a good resource.
https://codes.iccsafe.org/content/IPC2018
It may help prevent doing something that doesn't meet it.(Not in regard to your question but in general.)

EXAMPLE:

 

[frodo]

DIY Webber

tees are not allowed to be used in a horizontal position. [exception,,,does not pertain here]
to make a horizontal to horizontal connection you need to use
one of these 3 fittings



a horizontal to vertical
uses a combination laying on its back, or a long seep 90 not a short sweep



if you want to turn the horizontal main 90 degrees
you would use 2- 45 degree bends with a 24'' section of pipe inbetween making a long sweep
that willl not clog

 

[DIY Webber]

Got it. Thank you all.