Commercial Roof Replacement

NJ building code R907 generally allows one membrane recover (new membrane installed directly over the existing) if specific conditions are met: the existing membrane is dry and structurally sound, there's only one existing layer (no prior recover), and the deck and insulation underneath are in acceptable condition.

Recover saves the tear-off labor and dumpster cost, which can be a meaningful percentage of total project cost on large roofs. The catch: most premium manufacturer warranties (GAF Diamond Pledge, Carlisle Total Roof System 30-year, Sika Sarnafil 25-year) require full tear-off. Recover gets you a standard warranty class but not the premium 25-30 year non-prorated coverage.

We do moisture surveys with thermal imaging before recommending recover. Hidden wet insulation under the existing membrane invalidates a recover — the moisture stays trapped, the new system fails prematurely, and the warranty is voided when the manufacturer's inspector finds it. Tear-off is the only safe option when moisture is present.

On older NJ commercial buildings (pre-1990), code-driven insulation upgrades often force tear-off anyway because there's no way to bring R-value up to 2021 IECC requirements with a recover.

NJ adopted the 2021 IECC for commercial buildings. Most NJ commercial roofs replaced today require insulation upgrade to R-30 for climate zone 4 (most of the state including all major metro counties) or R-30 continuous insulation for climate zone 5 (Sussex, Warren, parts of Morris and Hunterdon — the northwest NJ snow zones).

R-30 typically requires 4-5 inches of polyisocyanurate (polyiso) insulation, which is the dominant commercial insulation board because of its high R-per-inch ratio. R-30 ci in northwest NJ usually means 5-6 inches.

The insulation upgrade adds 15-25% to total install cost vs membrane-only replacement, but it's mandatory at full tear-off. The energy savings recover the upgrade over 7-15 years depending on the building's HVAC load and how the prior insulation performed.

Tapered insulation crickets are added to direct water toward drains on roofs with inadequate slope. Many pre-1990 NJ commercial buildings have minimum slope and develop ponding regardless of new membrane quality — tapered insulation corrects this without re-framing the deck.

Most NJ commercial replacements are tenant-occupied — offices, retail, restaurants, medical, multifamily. Shutting the building down for a week isn't an option. Phased installation breaks the project into 5,000-10,000 sq ft sections, completing tear-off through final membrane install on each section before moving on.

Between phases, weather-tight protection is deployed — temporary membrane patches over phase boundaries, no exposed deck overnight. This adds 10-20% to labor cost vs an unoccupied install but keeps tenants operating.

Noisy work (tear-off, decking nail-down) gets scheduled around tenant operating hours where possible. Medical buildings get nights and weekends. Restaurants get morning hours before lunch service. Retail gets early morning or after closing.

Property management coordination is standard. We provide tenant notification letters in their format, deliver Certificates of Insurance to property management with the carrier and limits they require, and provide daily progress reports with photos so building owners and property managers can communicate to tenants.

Lease commencements force tight timelines. We schedule replacements to land before tenant move-in dates and treat those dates as hard deadlines, not soft targets. Coordination with HVAC, electrical, and sprinkler trades happens up front when those systems need to be coordinated through equipment-curb work.