Most synthetic roofing underlayments are designed to replace 30-pound felt. RhinoRoof is intended for applications where the 15-pound variety would be called for. Its maker says that the product is many times stronger than oil-saturated 15-pound felt yet provides twice the coverage, lies flatter on the roof, and costs about the same. It has a slip-resistant texture and is easily chalked, says the company. It’s suitable for use only with asphalt shingles. The manufacturer declined to provide pricing. InterWrap, 888/713-7663, interwrap.com
