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About JJM

Dennis Cohen


Our Story

Dennis Cohen, owner and operator of JJM Roofing & Construction has a long history in the roofing business.  In 1956 his grandfather started National Roofing Corp, now JJM Roofing & Construction since 2014.  Dennis began working with his grandfather in 1985 where he learned every aspect of the trade and managed roofing & sheet metal mechanics staff of over 100 employees.  Dennis has extensive on-site experience leading large projects (many exceeding $15 million) including the School Construction Authority, NYC Department of Design & Construction, NYC DEP, NYTA, CUNY Dormitory Authority, Montefiore Hospital, Federal Bureau of Prisons, USPS, Brooklyn Historical Society, and The United Nations.

JJM Roofing & Constructions master mechanics are experts in all types of shingle, Spanish tile , and slate roofs.  We work with copper gutters and leaders as well as foundation water proofing and dry wells.  We can handle any size residential or commercial roofing and siding project as well as all types of foundation waterproofing.  

My Personal Guarantee

JJM Roofing & Construction backs all of their work 100%.  We offer full lifetime manufacturer warranties on all new roofing.  We can also repair a roof under any manufactures warranty.  We use only the highest quality materials installed with precision and skill.  

We offer the highest quality Materials,
Service & Craftsmanship

Serving Nassau, Suffolk, Queens, Westchester, Brooklyn & Manhattan

What We Do