Seal gap between different styles of roofing
I recently bought a home and had the main roof stripped and shingled. The dilemma is there is a porch addition that has a metal roof. Leak is an understatement! I was told I should lift overlays of metal sheets and run a bead of silicone caulk the entire length then tighten screws back in place: easy enough the dilemma is there is a 2 inch drop from shingles to metal and a 2-3" gap between metal and siding. Even though I have no knowledge of roofing it doesn't take a rocket scientist to realize the flashing between was just hap haphazardly installed, it can be pulled away with very little effort and is allowing rain to drain from one roof to the other getting under the metal and causing leaks. Due to the fact the contractor was hired to fix this issue but instead took off after being paid, leaving me financially shot I need the least expensive "fix" for this gap, that I can do myself, to seal it and get me through the upcoming winter until I can $$ regroup and have it redone completely. I've heard that the spray can foam is and option but truly have no idea. HELP PLEASE.