Question for ATOT DIY homeowners (flashing a ledger)

[bignateyk]

See this image for reference:
http://pics.bbzzdd.com/users/bignateyk/ledger.jpg (http://hostedmedia.reimanpub.com/TFH/Projects/FH07FEB_FLABOA_01.JPG)
I am going to be installing a pergola attached to the house using a ledger board. I understand how the Drip Cap flashing and Z-Flashing works. That makes sense.

The part I don't understand is how the J-Channel and the vertical end of the ledger board works to prevent water from getting under the siding. Do I just caulk the hell out of the sides between the ledger board and the J-Channel? It seems to me the J-Channel wouldn't do anything to prevent water from getting under the siding along that vertical.

 

[JoeBleed]

Can you just make it freestanding so it isn't attached to your house? Essayist way to avoid leaks and rot.

 

[kevman]

Can you just make it freestanding so it isn't attached to your house? Essayist way to avoid leaks and rot.

Yup, that is exactly what we did at my parents house some 20 odd years ago. Thing is solid as ever.