Waste line backfill question

[ineedagarage]

Hello all


I need to run about 30 feet of drain line and water supply lines under my garage floor before I concrete. I have two questions should I use schedule 40 pipe or 80? Also whats the best way to backfill sand, rock, just dirt?

 

[pstnbly]

Bed the pipe in 3/8" crushed stone, it will hold the grade better than sand, backfill to 6" to 8" over the pipe with sand, then common fill if you wish, compact in 12" lifts

 

[K'ledgeBldr]

In a typical residential type application I see no need for sch. 80 pipe. Usually, the best backfill is what you took out of the trench. Just be sure you have continuous support of the drainline before backfilling.
IRC (International Residential Code) says that you can put the supply line in the same trench as the waste line (depending on materials) but, I do know for a fact that some convening authorities still require separate ditches- check with your local building department.