I doubt that that is the root of the problem though.
Gap between roof sheathing and fascia.
The correct placement of a roof drip edge is on top of the roof s exterior cover directly between the sheathing and the fascia board which forms a drainage gap between the drip edge and the fascia board.
The staining on the fascia suggests that this bat problem has been going on for a while.
On my shed my sheathing does not protrude actually how both my house and shed are done is a 1 x 6 house 1 x4 shed fascia is installed to end of rafters then 1 x 1 1 2 is tacked onto the fascia at the top.
This material should have extended all the way to the bottom ends of the rafter joists where the roof deck meets the fascia board basically the area where the gutters are hung.
Why is a drip edge important.
Re the fascia gap it is normally installed tight often the fascia is even installed up tight to the shingles so that the roof sheathing is butted to the inside of the fascia.
The worst part looks about 10 long but i can t see the whole roof since it is too high.
I think that this practice differs by region though.
Slowly move down the joint to apply a steady bead of caulk into.
The gap between the roof sheathing and the fascia may be small but it was all the space that bats needed to get into the attic of this house in atlanta.
Builder looked at it and said he d have one of his siding guys come out and install flashing to fill the gap.
Cleaning gutters and notice 1 5 gap between roof deck and fascia board.
The roof sheathing comes down and ends on top of the 1 x fascia.
Then i do a metal drip edge to cover it all.
Smooth the caulk bead with your finger and begin caulking the joint between the fascia board and the soffit also known as the eave.
As a result the drainage improves water flow and protects the roof from potential water damage.
Unfortunately in most homes this is not the case.