How to attach a deck ledger board to house joists
This is a tricky situation....
Normally there would be a rim joist at the edge of your framing which you could attach your ledger to. 

This is what I would do for a really beefy construction:


Gain access to the inside and install full height blocking between the joists.  
Install a rim joist on the exterior and connect the blocking to the rim joist so they form one unit.   
Install hangers or angles to connect the blocking to the joists on the interior. 
install waterproofing (flashing over the exterior rim joist) to create an continuous waterproofing layer on your exterior wall. 
Install your ledge board with spacers at the lag bolts to form a gap between the ledge board and flashing of about 1/2"


This construction would accomplish two things:


Avoid any attachment into endgrain of your joist. Don't even try this. Screwing into endgrain is weak. That is why we use angles...or even hangers.
Create a continuous water proofing layer at your exterior wall
Create an air gap between wall and ledger to avoid rot. (This is my personal take. Attaching this way would need to be confirmed with the Building Department)


To properly and legally do this you would get input from a Structural Engineer and a building permit.