I was reading an article in the identifying you as the home improvement Guru. I spoken to an expert who came to my house told me my shingles were not lifted so he could shingle over the existing ones and it would be cheaper and a better insulation. My house is 14 years old, most homes around me have had their roofing replace and the old shingles removed. Oh great guru what do you think? Again sir, I'm awaiting your response before I make any decision.
Answer:
I don't know that being a Guru or expert is exactly where anyone wants to be but as regards the roof, the shingles must come off. If I want insulation I'll put it on the attic floor not the ceiling. My purpose being to not permit heat to escape to a part of the house that is, hopefully, not occupied. I cannot think of a single asphalt shingle manufacturer that suggests applying a second layer and I have yet to hear you talk about ice and water shield, tarpaper and ridge venting. These are all topics you'll want to familiarize yourself with prior to signing a contract.