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/

Penn Barry
Manufacturer of centrifugal and axial fans for commercial and industrial applications. Also makes a line of roof vents and curbs for roof intake or exhaust.
http://www.pennbarry.com

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/

Curbmaker Concrete Landscape Curbs
Concrete Curbing Business Opportunities Business Opportunity in concrete curbing, Curb Maker can help you start your own successful concrete curbing business in Canada, USA or Europe. Curb machines
http://www.curbmaker.com

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 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/

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

American Hydrotech, Inc.
Hydrotech’s Green Roof, the Garden Roof Assembly is the latest innovation in roofing/waterproofing using MM6125 and 40+ years of successful installations around the world.
http://www.hydrotechusa.com/

Roof Menders
Tin Roofs: protecting our rich heritage against leaks and rust
http://www.roofmenders.com/

Roof Builder Tools
Architects using this AutoCAD shareware can quickly create any complex 3d roof model, then extract 2d elevations from them. Extrudes your your 2d roof plan into 3d solids.
http://www.roofbuildertools.com/