CertainTeed shingles are known for their premium quality and comprehensive warranty. GAF shingles are recognized for his or her total nice worth and a variety of kinds. That said, the most well-liked model of asphalt shingles in the US for mid-vary properties is GAF Timberline HDZ architectural aka dimensional shingles. Ice and WaterThat’s why valleys should be lined with and protected by a moisture barrier that covers each side of the valley by inches. Many roofing contractors in climates with freezing winter weather also like to put in a layer of moisture barrier at the eaves the place ice dams may type. GAF’s moisture barrier is known as WeatherWatch and Owens Corning calls its product WeatherLock. Repair is costlier on a per sq. foot foundation because it is extra time-consuming to combine new shingles into the existing roof “here and there” than to install them over the whole roof.