Will need to hire a roofer/contractor to fix this problem around the chimney. It's leaking down the side of the house under the siding, and causing wet spots along the walls/ceilings of the 1st and 2nd floor on that side of the house. I want to be knowledgeable before dealing with any quotes. What is the main problem here and roughly how much should I expect to pay (already have all the shingles and materials). Just so I don't sound too uniformed when they show up.

Thanks to earlier posts on the forum, I've gotten up on the roof and cut back siding that's been touching the roof shingles / had to be wicking up moisture. Our roof was replaced 2 years ago and the guy overall did a crap job / we didn't pay him all that was due. So whatever needs to be done now, is on me / hiring someone else. Not sure of the correct words to describe this, but I'm talking of the top edge of roof shingles that butt up against the siding in this question (see pics). There's a bulge in a top shingle. [url]https://youtu.be/VxKT81qK1Mo[/url] Conceivably, moisture can get under this shingle because it's lifted off the shingle below it. This roof is over an overhang of an outside 'porch' , so water won't get into the house through this route. Any thoughts on how to deal with this? Make a cut in the shingle from top downward and overlap the 2 sides of the bubble with roofing cement under it? Something else? And for the other 2 pictures - that nail head and the 'tear' in the flashing? Normally, there's a shingle that goes under the flashing and then one goes on top? So for both the bulge and these, water getting under the top shingle doesn't usually go into the house? But they DID do a crap job overall, so who knows how they finished things. I am thinking I can slip another piece of flashing up and under the siding and then under the shingle? Would you have an adhesive on the bottom / top of the flashing? Specifically what would you use? I see karnak #19 in caulk tubes at Home Depot. IS that good? THANKS!