I want to attach a ledger board, over the existing wood siding. Something similar to this, but immediately underneath the roof
How do I determine where I need to drill the holes to attach it to the siding - basically, how do I find the joists?
An additional complication is that there is just a small distance between the roof and window edge
Are there any drilling recommendations, to avoid hitting wires or whatnot?
Since the new rafter section will cover any siding you may remove, layout how far the rafter section covers the siding and cut it about a 1/4 to a 1/2" lower. This will let you find the framing pretty easily, even remove a little subsiding to confirm, careful how deep you set your saw. This will show any conditions you may need to attend to. Set the bottom of the ledger at the on a chalk line set at the level you predetermined before you cut the siding. Set a ledger at the top of the rafter section as well to control rotation of the new section. This is an expansion on what Comintern suggested with his ledger and joist hanger idea, make sure the joist hangers approved for your framing condition.
Here is a little sketch to help illustrate. Doing it this way will allow a finished ceiling to go uninterrupted to the existing wall.
First remove your current fascia board.
Splice to the ends of your current rafters by sandwiching boards (cut to pitch) on both sides of each rafter.
This will allow you to continue on your roof's current pitch.
However, by doing so, this will eliminate any view or scenic visuals that your current windows provide.
Hopefully this will help you... or at least give you an idea.
