Hello, my house was built in the 80s and is located in the NE United States.. I recently had a handyman in to do some work outside replacing some rotten wood and he said it looks like some corners were cut when the house was built, the builders did not install 'flashing' around the edges of the roof, and the roof doesnt overhang the siding in many places. Also he said the house doesn't have a 'membrane' layer, which is is a more recent requirement.. As a result water can get behind the siding and cause rot. He thinks that the roof shingles need to be replaced in order to install the flashing. I think the shingles are in pretty good shape. Its not the original roof, but it is at least 10 years old. I dont want to get a new roof if I dont need to. He knows a roofing guy who will take a look, but I plan to get an independent roofer to check as well. Does the bit about flashing sound correct? And can flashing be installed without replacing the whole roof? Thanks