I'm running 2" PVC from my house to a detached garage to run a 60 amp feeder. Looking at the NEC, it looks like I need to put it in SCH 40 below-ground. However, it looks like I have to use SCH 80 anywhere the PVC will be above the ground. Is that correct, or can I get away with using SCH 40 for the whole run?
352.10(F) says that the PVC conduit "used exposed in areas of physical damage shall be identified for the use". I know schedule 80 is suitable for protection from physical damage, however, the Authority having jurisdiction in your area may allow schedule 40 as well. You'll want to check with your local inspector to be sure, or use schedule 80 for the exposed section.
300.5(D)(4) says that even though the conduit is buried, if it's subject to physical damage (not deep enough, under a garden, etc.) it still has to be schedule 80.
The safe bet, is to use schedule 80 the whole way. If the conduit is protected from physical damage, you can use schedule 40 the whole way.