I have a built-up roof I would like to eliminate although it has served us well. The problem is that the gravel surfacing finds its way onto the shrubs and lawn. What is the minimum pitch that shingles can be applied effectively? Is there any other roofing material that I might use? Eleanor V. Ash Orlando, Florida
A Roofers and roof manufacturers prefer a 4-in-12 roof pitch to justify the use of shingles. While 3-in-12 is sometimes passable, it is not pleasing to the trade. On the other hand, 2-in-12 or 2 1/2-in-12 roof pitches are maximum for built-up roofs, else the gravel be unduly blown or washed off.
Check with a local roofer for a type of spray-on-roofing foam made of urethane. It is a good insulator and adheres to the existing roof if the roof is in proper condition.
This overlay roofing may be your answer.