New Construction - Basement Slab Roughin

[dondiy]

I am building a 24' x 44' cabin. Plans have been approved, foundation walls have been poured and am roughing the plumbing in the basement before the slab is pour. The basement has 8 foot tall walls.

There is a kitchen sink on first floor.
Full bathroom on first floor (sink, shower, toilet).
Full bathroom on second floor (sink, tub, toilet).
Floor drain in basement.

Each 3 set of fixtures is just above the stack individual stack in the basement.
All 3 main stacks will be vented out the roof.

Basement slab design (see attachment) is 3 stacks draining to basement, and a floor drain all emptying into a 4" pipe that leads to the septic tank. Cleanout just outside the foundation wall before septic tank.

1)If all three stacks coming from the first floor are vented to the roof, do I still need an additional vent in the slab?

2) Do I need a cleanout inside the basement if I have a cleanout just outside?

3) To pressure test the system, do I just:
a) plug the 3 stacks, floor drain, and connection to the septic line
b)pressure the pipe with air
c)assure no leaks for 15 minutes

Thanks for your help
Don DIY

[markts30]

1)If all three stacks coming from the first floor are vented to the roof, do I still need an additional vent in the slab?

2) Do I need a cleanout inside the basement if I have a cleanout just outside?

3) To pressure test the system, do I just:
a) plug the 3 stacks, floor drain, and connection to the septic line
b)pressure the pipe with air
c)assure no leaks for 15 minutes

1) If the floor drain is adequately vented, there shouold be no need for any additional vents (beyond the other floors that is)
2)External cleanout should be good enough - include cleanouts in each fixture group as well - if there is a problem later you will be glad you did
3)Yes you can use air - only use 5PSI though...
We generally use a 10' head of water for underground testing (and above ground if there is no drywall up yet...)

[dondiy]

Thanks for the help.

Just a couple of clarifications:

1) Looking at the PDF, is the pipe layout correct? Does it make sense to connect all three stacks to a 3" pipe running down the center, or would it make more sense to run a main pipe diagnally from the furthest stack to the septic pipe to reduce pipe?

1) Looking at the PDF, is the drain vent adequately vented? If not, where/how would I put the drain vent?

Thanks again for you help.

Don