I hired a roofer who installed a new roof using Timberline 300 Architectural shingles. He used "rubberoid" on the back because the back is more flat than sloped. On the front he used the rubberoid for three feet as an ice and water barrier, but I noticed he laid the shingles directly onto the plywood after that. On his estimate he indicated 15lb tar paper but I never saw him use it. Is the tar paper supposed to go down under the shingles? The second questionable move was that I had him replace my fixed skylight so that I would have a manual venting skylight. The issue at hand is that the new window looks much smaller and actually was narrower than the old one. My concern was that the sides didn't drop in and I could see the sky through the sides. He caulked it and said it would be fine. Did he order the wrong size or does this seem reasonable? Thanks bunches, Donna:)

Please excuse the simplicity of this question. A few years back I built a small garden shed about 10x8. I put shingles right on top of the sheathing...no felt. To date I have had no leaks or roofing issues. To be honest, I didn't even know about felt. Now I am about to cover a new 8x8 section of roofing that extends out from the house over a patio (a 'shed' roof). Do I need to put felt down? Does felt simply act as an additional water barrier or does it have an additional purpose? The felt seems to come in big rolls that would last me a lifetime. Is there some other common material I could use for an 8x8 surface to put under the shingles or should I bite the bullet and buy one of those giant rolls?