Roofing question..gable porch roof into vertical board and batten?

[Woody Stover]

I want to fix this trash work, done by my wife's grand-dad and his buddies when they built this place. I don't think any were pro roofers, and liberal partaking of liquid refreshment may have been a factor.
I have enough shingles left over from when I re-roofed, a few years back. I'm thinking I just come straight into the board and batten gable end of the house with the shingles, but how do I trim it out, aluminum flashing, or...??

Here are the shingles I have:

 

[Medic21]

Proper way would be to get the flashing completely behind the siding.

Personally I would chalk a line and cut it evenly and get aluminum at least 6” up behind the siding.

 

[MTY]

What he said with one caveat. I might purchase a pre formed piece of flashing that came in a color that closely matched the shingles or the siding color. Think pole barn or metal roof flashing. If you do not have a break, the pre formed will me much more uniform and look a lot more professional.

 

[AlbergSteve]

What I've done on jobs like this is carefully remove one batten and one board to create an opening on the wall, using that opening as a ''door'' to insert then slide step flashing behind the siding as you work your way up the roof. Cut the siding up about 2 inches and remove any nails that are closer than 4 inches to the roof. The bottom course will need a bit of custom metal bent/worked in there. If you can't remove the siding, I've often been able to slide the step flashing behind the siding at the gap created when you cut the siding a couple of inches above the roof.

 

[Woody Stover]

insert then slide step flashing behind the siding

There is no wall behind the board and batten, it is just nailed to a cross-board half way up. The board and batten is the only "wall." Here's a pic from inside the attic.

I might purchase a pre formed piece of flashing that came in a color that closely matched the shingles or the siding color.

We've been discussing it more, and are now considering eventually putting a shed roof porch across that side of the house.
In that case, I might just get that flashing in a matching color and go under the battens, but on the outside of the boards. Then seal the flashing and the sides of the battens with caulk. Half-assed, yeah, but can probably get away with it since it has an overhanging roof deck/rafter and weather hardly ever comes from that direction. Where those old shingles curve up to the wall, they are sealed with probably 80-yr-old roofing cement that has pulled away from the boards. Any water that has been getting through has been shed off I guess, as there's no visible damage to the drywall inside, which is mounted to the logs with no insulation.
We're painting the board and batten, and the sage-color window trim was painted as well, to better match the brown in the logs. You can still see the sage around the door framing. The orange door will also be muted down a couple of shades.
Actually, she has been doing most of the painting. I've been in the woods, "busting Ash."

 

[AlbergSteve]

Looks like the b and b runs down behind the small dormer gable so probably little chance of water getting in to the house.

 

[Woody Stover]

Looks like the b and b runs down behind the small dormer gable so probably little chance of water getting in to the house.

I probably should have fleshed out the actual construction of the wall at the beginning, so you guys would have a clearer picture. But I learned something, even if it may not be applied in this particular case..thanks.
More questions coming...I don't know how to construct a porch with a shed roof, and fasten it to the cabin. Might have to get a pro for that one, but there are so many hacks out there that I'm leery. I can screw it up just as bad as they can, and for a lot less money.

 

[Hogwildz]

new shingles run into steps flashings, step flashings up behind siding, accept at bottom. Last step flashing outside the siding to keep water from running behind the siding. Or leave enough gap between bottom of the last step flashing, and bottom of the siding above it, then with a proper cut on the bottom part of the step flashing, you can bend, and fold the flap and angle the bottom edge of the step flashing outward to direct water away from the house/siding, into the gutter.

If you go with a porch roof, DO NOT mount any part of the flashing where it meets the wall, on the outside and caulk or try and seal it on the outside. It WILL fail, and leak in time. Cut the bottom of the siding out, and run the flashing up behind the siding. It is not very hard especially with B&B.

 

[billb3]

Doesn't look like there is flashing on the bottoms of ANY of those vertical boards. Technically there should be flashing at the bottom of the board and above what appears to be a quarter round trim so that water can't travel around the bottom of the board.

Do you have the patience to put a second layer of vertical wall so you can put the step flashing like it should have ?

 

[Woody Stover]

I assume the bottom ends of the boards terminate below the top of the log, on the rounded curve, and that the water runs down the outside of the log. Maybe I can get a better look at that in the attic..I have to go up there today anyway.