I am going to be adding a gabled porch on the front of my house. We have been remodeling for 2yrs, and are now trying to finish the exterior. I am a fair at framing & roofing and, I am able to do the work myself. The question I have is, can I tie into the existing roof without cutting into it? Is a double header needed to secure the ridge board? Here is what it looks like now. Thankyou for any input.