3" or 4" PVC for septic

   / 3" or 4" PVC for septic #11  
Re: 3\" or 4\" PVC for septic

The reason the shower gets a bigger drain is that the pan is shallower, it won't hold as much accumulated water as the tub can.
 
   / 3" or 4" PVC for septic #12  
Re: 3\" or 4\" PVC for septic

That paper pipe is orangeberg and we have it here in our city on lots of old houses. I guess if it worked for 100 years it can't be all bad. I looked at a 1932 built house on Friday with copper drain lines all soldered in 4 inch on down sizes,I really expected cast iron on that one.

I would use 4" on the outside line just because that is traditional. Larger pipes can have flatter slopes and still flow thae same water. Here in my city we allow 6" side sewers at 1% and 4" at 2%. 3" is not allowed outside the home.
 
   / 3" or 4" PVC for septic #13  
Re: 3\" or 4\" PVC for septic

Farwell,

I read the CA building code requires copper pipes. The plumbers pushed this into the code so they could make more money. I thought that it only applied to supply water not waste. There was an article a while back in the Journal of Light Construction regarding this part of the CA code.

Later,
Dan
 
   / 3" or 4" PVC for septic #14  
Re: 3\" or 4\" PVC for septic

Dan,
California does not require copper for waste pipe but San Francisco does. San Francisco has very strict codes and enforces them, probably because of the fire that went along with the 1906 earthquake. San Francisco is still another disaster waiting to happen.
I would have thought the copper would save time over cutting and threading iron pipe. I would much rather use copper over iron any day.
Farwell
 
   / 3" or 4" PVC for septic #15  
Re: 3\" or 4\" PVC for septic

Dave,
That makes a lot of sense to me. I use all 2 inch pipe on any drain I have to work on and a lot of times I use the heavy black glue together pvc pipe fittings for "P" traps under my sinks
Farwell
 
   / 3" or 4" PVC for septic #16  
Re: 3\" or 4\" PVC for septic

Highbeam,
I thought the paper pipe was cast iron until I tried to cut it with a hacksaw. I had never heard of it before.
The 3 and 4 inch copper pipe should last for a long time.
Another thing that surprised me is the lead water pipe that is still in use in San Francisco in some of the old neighborhoods.
Farwell
 
   / 3" or 4" PVC for septic #17  
Re: 3\" or 4\" PVC for septic

whatever size, go to a plumbing supply place for the belled end pipe sch40 pipe.

Dont mess with couplers.
 
   / 3" or 4" PVC for septic #18  
Re: 3\" or 4\" PVC for septic

Highbeam has it correct, The larger the diameter the pipe the less slope it requires for draining. 4" diameter is the smallest used in the industry outside. The smaller pipes inside the house tend to grow in diameter as more pipes interconnect to prevent blockages and better flow. It is common in many houses to have 3" diameter main stacks, as well as 4" diameter. Outside should be 4" diameter, and if it will have a load on it like a driveway or driven on etc. use sch. 40 pvc. Pack the trench bottom with a layer of sand, it will make holding the slope easier while installing. Install a clean-out to the surface if the length is greater than 75 feet, in my opinion.
ps, a higher velocity within the pipe is not actually good, it can accelerate the "sanding" of the bottom of the inside of the pipe. A good flow is between 2 ft/s and 12 ft/sec. But that gets into hydraulics and I don't think this is that complicated of a project. Good luck with it. Have fun.

Dave
 
   / 3" or 4" PVC for septic
  • Thread Starter
#19  
Re: 3\" or 4\" PVC for septic

</font><font color="blue" class="small">( whatever size, go to a plumbing supply place for the belled end pipe sch40 pipe.

Dont mess with couplers. )</font>

rdln, I've never used the belled end pipe (blue color). Why do you recommend this over 'glued' pvc? thanks.
 
   / 3" or 4" PVC for septic #20  
Re: 3\" or 4\" PVC for septic

White belled end schedule 40 pipe is a glue joint. It provides at least 6 linear inches of mating contact (careful now /forums/images/graemlins/blush.gif)
instead 2 inches (per pipe) with a coupler.

ummh! make joint strong like bull.
 
 
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