The Gem companies have been certified by all major manufacturers including:

• Manville (NDL Status)
• GAF (NDL Status)
• W.P. Hickman (NDL Status)
• Siplast
• Tamko
• T. Clear
• DOW Chemical
• Hyperlast Hyperlast (Plural Component Systems - Parking garage and IRMA Roofing Systems)
• Triflex
• Soprema
• Landmark Status in New York & New Jersey
• GFRC
• TerraClad (Boston Valley Terra Cotta)