Decra Roof Systems:
Roof coverings using lightweight roof tiles for all roofs down to a ten degree pitch. UK.
http://www.decra.co.uk/

Roof Genius
Roof calculator, calculates a detail list of roof materials, and a complete estimate. Two ways to determine roof pitch. Offers tips and how to's on roofing. [Windows 95/98/2000/Me/XP/NT]
http://roofgenius.com/

Dallas Metal Products, Inc.
Providing all you're metal products and metal roofing products since 1989
http://www.dallasmetalproducts.com

Elastomeric Roofing Systems
Ersystems is a manufacturer and distributor of high performance elastomeric coatings and membranes designed for the roof restoration and re-roof markets.
http://www.ersystems.com/

Thaler Metal Industries Ltd.
Designs, manufacturers and markets roof penetration protection products. Provider of flashings, roof drains, equipment support systems and anchors to the roofing industry in North America.
http://www.partsdome.com/thalermetal/

Rib Roof Inc.
Design, manufacture and installation of metal roofing and self-storage building systems. Includes a construction specification handbook, product specification sheets and a rib roof technical manual.
http://www.ribroof.com/

Roof Products, Inc.
Manufacture prefabricated roof curbs and other roof accessories. Products include expansion joints, equipment supports, adapters, and ice deflectors.
http://www.rpicurbs.com/

Roof Coatings Manufacturers Association
Roof Coatings Manufacturers Association (RCMA) represents manufacturers of cold-applied roof coatings and cements. RCMA’s site offers product information and the latest roof coating news.
http://www.roofcoatings.org/

Superior Steel Components, Inc
Supplies pre-fabricated light gauge steel components, including roof trusses and wall panels, for commercial and residential buildings. Provides metal roof deck and floor joist systems.
http://www.lgst.com/

Fibreglass Roof Decking
Roof Decking From Dura Composites Ltd
http://www.roofdecking.co.uk