This product is no longer available
Perforated glass-reinforced venting layer which is saturated and then coated in polymer modified bitumen. A fine sand finish is applied to the top surface and a sacrificial film to the back surface. The sacrificial film over the perforations melts during application of the underlayer and allows bitumen to flow through the perforations and spot bond to the deck.
This product has been archived and is no longer available for project specification within NBS. Archived data may not reflect the manufacturer's most current version of the product.