Made from durable and strong, internally reinforced polyethylene laminates, the Griffolyn® roof vapor retarder and barrier system withstands extreme temperatures and is highly resistant to punctures and tears. Griffolyn® roofing vapor retarders are available in stock sizes, which are available for immediate shipment and can be manufactured in sizes to meet project requirements up to 200' x 200' (61 m x 61 m), greatly reducing in-field seams and the potential for failure.