How Much Does Roof Deck Repair & Replacement Cost in NJ?

Re-decking a roof runs about $2 to $5 per square foot per HomeGuide, which puts a national average near $5,500, while Angi places the range at $2 to $6 per square foot. HomeGuide attributes roughly $1.50 to $3.00 of each square foot to labor, and a hidden-rot re-deck discovered and replaced during a re-roof adds about $50 to $120 per 4-by-8 sheet per Refined Home Services / HomeHero contractor cost data.

New Jersey pricing sits 10 to 40 percent above the national figures, with labor making up roughly 60 percent of a repair total, per Integrity Home Exteriors. That premium reflects regional labor and access costs rather than a different scope of work, so a square-foot quote in Essex County tends toward the upper end of the national ranges. Because the amount of sheathing replaced varies with the extent of decay, no whole-project dollar total applies to every roof, and the work is quoted from a free written estimate after the deck is examined.

Raw OSB sheathing runs about $20 to $50 per 4-by-8 sheet and roofing-grade plywood about $50 to $80 per sheet, per Colony Roofers / Fixr / Angi, so OSB costs less than plywood per sheet. Those are material-only figures; installed re-decking carries labor on top, which HomeGuide measures at $1.50 to $3.00 per square foot.

The material choice is a moisture-resilience-versus-cost tradeoff rather than a quality ranking. Plywood is cross-laminated, dries more uniformly, and partly recovers after wetting, while OSB swells at the edges and delaminates irreversibly once saturated, which is why saturated OSB is re-decked rather than dried out, per InterNACHI and trade guidance. Both panels carry an APA span rating and either one grips a roofing nail at least 3/4 inch deep, per ARMA, so each one anchors the covering when specified to the correct thickness for the rafter spacing.

Panel thickness, set by the rafter spacing through the APA span-rating system, drives the material specification and the cost. The APA span rating gives the maximum rafter spacing each panel carries: 7/16-inch panels rate 24/16, 15/32-inch panels 32/16, 19/32-inch panels 40/20, and 23/32-inch panels 48/24, where the first number is the maximum rafter spacing for roof use, per APA - The Engineered Wood Association. InterNACHI cites 5/8 inch at 24-inch rafter spacing as conservative guidance rather than a code minimum, and the enforceable rule is IRC R803.2, which requires H-clips, tongue-and-groove edges, or solid blocking on panels under 1/2 inch over rafters spaced more than 20 inches on center.

The extent of decay sets whether the job is a localized panel repair or a full re-deck, which is the largest single cost driver. Contractor consensus replaces the deck when damage exceeds 25 to 30 percent of the roof area or when one repair approaches 50 percent of replacement cost, and replaces localized panels for limited decay. IRC R908 prohibits roofing over a water-soaked or deteriorated deck, so unsound sheathing exposed at tear-off is removed before re-covering, which is when a hidden-rot re-deck at $50 to $120 per 4-by-8 sheet per Refined Home Services / HomeHero is added to a re-roof.

Permitting affects the total differently for homes and commercial buildings. Roof-covering repair or replacement, including re-decking exposed at tear-off, on a detached one- and two-family dwelling is ordinary maintenance with no construction permit under N.J.A.C. 5:23-2.7, while a structural change to rafters or trusses triggers a permit. On a commercial building, repairing more than 25 percent of the total roof area within a 12-month period requires a permit under the same NJ Uniform Construction Code rule.