Most building codes allow two layers of organic or fiberglass asphalt shingles on roofs with a 4/12 pitch or less, and three layers on steeper roofs. If the structure can support the added weight, a typical 20-square (2,000-square-foot) reroof will cost at least $1,000 less than a tear-off job. Labor savings go beyond demolition: Not having to lay down felt paper saves $10 a square; and site and weather protection, as well as cleanup, are all reduced if not eliminated. Disposal costs are lower, too, because we don’t have to rent a dumpster and we save the $65-per-ton dump fees. We also save by not having to separate the recyclables. Here in central New York, asphalt, cardboard, and wood all have to be tossed into different containers, and in some cases hauled to different transfer stations. The same is true of flashing, drip edge, tar buckets, vents, and other scrap metal.

As a contractor in a highly competitive business, I can’t claim that a reroof is a lot more profitable than a tear-off job, but I can say that it’s much less risky. There is no chance of a dumpster carving up the lawn or scarring the driveway; there is less risk of property damage from falling debris or from nails that find their way into...

or Register to read the full article.