I'm doing a re-hab on a house and we want to cover an existing porch that is 9' wide. we are planing on going 2' up the 6/12 roof removing the sheathing and tying the new rafters to the old. Any recomendations on tying these together. also wondering whether we should lower the ceiling height for this room to give us more pitch on this roof. soffit from original house will extend and wrap this roof. half of this area will be utility and the other half will be a screen porch.any help will be appreciated