| Resources: | |
| ElkCorp.Com | Elk has led the way in improving the quality of roofing products since 1955, the year they opened their first production plant. That history of innovation continues today with their industry-leading roofing products. |
| GAF TimberLine | Founded in 1886, GAF Materials Corporation has grown to be North America's largest commercial and residential roofing manufacturer. |
| 3rd Party and International links (For informational and comparison value): | |
| None Listed | |