Roofing question!?

A section of my roof is over a screened in porch. The porch is on footings so I have added windows and a new door to make it a year round living space. The slope on this section of the house is less than 3/12 and there is a rolled roof on it. I heard that when the roof is less than 3/12 rolled roofing is necessary. I want to add skylights and a new roof. I am in Wisconsin. If I put down strips of ice and water shield and overlap them across the roof from the bottom up could I then possibly shingle over that.