Decks, Patios, Porches and Docks - Do I need a ledger board?

I am replacing some rickety old steps out the back door with a 4'x4' porch and 4 steps leading from it to the ground. Using 2x6 decking, I am planning only four joists. The below url is about the best picture of a ledger board, flashing, etc I could find. I was just wondering why I even needed a ledger. I was thinking about just drilling two 3/8" holes through the band/rim joist (labeled "2" on the below diagram) and into the end of each porch joist, and running a pair of 12" 1/2" lag bolts from the inside of the house out into the end of each porch joist. The ledger would be secured to the band/rim joist anyway, so I'm not seeing the benefit to having a ledger in the first place.

http://www.bestdecksite.com/images_intro/ledger/ledgerBoard_w.jpg

You don't want to sink 3/8" lag bolts into the ends of 2X6's -- the 2X6's will split eventually, and the landing will collapse.

Install the steps as shown in the diagram that you posted, making sure that the flashing is done correctly. And if you are using ACQ PT lumber, DO NOT use aluminum flashing.

An alternative to the ledger would be to make the landing free-standing. That would require 4 footings -- one at or near each corner of the landing.

You don't want to sink 3/8" lag bolts into the ends of 2X6's -- the 2X6's will split eventually, and the landing will collapse.

I mentioned 2X6's for the decking only to establish joist spacing requirements. The joists would be at least 2X8's.

I have also seen various places saying to connect my two outside joists to the outside ends of the ledger board by putting fasteners into the end of it. I can't find anything stating a size though, so I was probably going to use three 3/8" lag bolts. Are you saying this is too large of a fastener to screw into the end of a 2Xanything? What is recommended? I also would be putting fasteners into the ends of my stair stringers, again 2X's.

You don't put 3/8" lag bolts into the butt end of a 2X. They won't hold because the are running parallel with the grain, and they are too large -- you wouldn't have enough wood left beside the bolt.

The "fasteners" that you are talking about putting into 2X's are nails, and #8 or smaller screws.

And don't install the landing without a ledger, or a rim joist across the end of the joists. This is there, amongst other reasons, to keep the joists from twisting or laying over.