In 1985 we built a carport onto our low sloped house roof attaching it per building codes to roof rafters. A few years later our shingles cracked where the two roofs join, which could have been caused by the carport posts settling. We are now going to shingle and are wondering of we should remove some of the plywood on the roof and re-install a few sheets over the joint in order to strengthen the area where the two roofs join? The length is approx. 30 feet. Also, do you recommend shingles or roll roofing on a low slope roof?
Answer:
That transition from one slope to another is always a problem so make sure you have a good layer of ice and water shield under no matter what kind of roofing material you use. I have always preferred regular shingles applied in low slope fashion to rolled roofing unless its a small structure. At 30 ft. long, yours is not a small structure.