Which Is Better: Asphalt vs Slate Roofing?

Asphalt shingles install across northern New Jersey at $5.50 to $11.00 per square foot, while natural slate runs $10 to $30 per square foot, roughly $1,500 per square, per Josten Roofing's NJ figures and NJ roofing guides.

Asphalt shingles split by profile within that range: 3-tab installs at $5.50 to $9.50 per square foot and architectural at $6.50 to $11.00, per Josten Roofing, defining the entry tier for an Essex County reroof that lands near the $10,000 to $11,000 national asphalt-replacement benchmark on a typical home. Repairs stay modest, because minor patch or flashing work runs $360 to $1,550 per Angi, and a New Jersey roof leak repair runs $400 to $1,000 per HomeAdvisor, since NJ pricing sits about 10 to 15% above the national average.

Natural slate is the highest-priced covering on the historic homes of Montclair, Glen Ridge, and Newark's landmark districts, yet it repairs tile-by-tile rather than in whole sections. A single broken slate replaces for $50 to $300 per HomeGuide, and slate repair averages near $1,400 within a $500 to $2,100 band, because the stone is sounded, flipped, and reset rather than patched, per NPS Preservation Brief 29. Asphalt shingles reach a full replacement once damage exceeds 25 to 30% of the roof area per contractor consensus, with the 50% rule favoring replacement when one repair approaches half the replacement cost, while natural slate reaches replacement only when 20% or more of its slates are broken, missing, or sliding, per NPS Preservation Brief 29.

Natural slate outlasts its own fasteners and flashing, so New Jersey freeze-thaw failures trace to corroded fasteners and degraded valley flashing rather than the stone, while asphalt shingles crack and curl after years of freeze-thaw, per NRCA and InterNACHI guidance.

Natural slate weathers to surface sugaring on lower-grade stone rather than structural cracking, per NRCA and the National Slate Association, so a sound slate field stays intact while its components age. It is a heavy quarried-stone covering whose structural load is reviewed before installation, and it carries a non-ferrous fastener rule: solid copper or stainless-steel nails, because plain or galvanized steel rusts out long before the slate, per NPS Preservation Brief 29. Asphalt shingles are a light covering that loads any properly sheathed roof with no structural upgrade, then fail through wind-driven granule loss, edge and tab curling, and thermal-shock cracking along the cutouts, per NRCA and InterNACHI guidance.

Asphalt shingles depend on an ice-and-water shield at the eaves, required at eaves with an ice-dam history and extending at least 24 inches inside the exterior wall line, per IRC R905.1.2 as enforced under the NJ Uniform Construction Code (N.J.A.C. 5:23). Natural slate on a landmark property in Newark's James Street Commons or Lincoln Park district triggers a Certificate of Appropriateness from the Historic Preservation Commission, per N.J.S.A. 40:55D-107, before a roofing-material change, a code path that adds a municipal review step asphalt outside a historic district does not face.

The deciding factors are the ownership horizon, the budget, and whether the home sits in a designated historic district, because one slate installation spans the period across which asphalt is replaced three to four times, per the InterNACHI chart. The lifespans set the frame: asphalt lasts 20 to 30 years and natural slate 60 to 150, with the National Slate Association rating ASTM S-1 slate at a 75-year minimum.

The ownership horizon and budget favor asphalt shingles when the plan runs under 15 years or the budget caps near the $10,000 to $11,000 national asphalt-replacement benchmark, since asphalt installs at $5.50 to $11.00 per square foot. Within asphalt, 3-tab lasts about 20 years and architectural about 30 years per the InterNACHI chart, and the NRCA notes actual asphalt life varies up to 40% with climate, installation, and maintenance. Architectural asphalt replicates slate's layered, dimensional profile, installs at $6.50 to $11.00 per square foot, and offers the slate look at one-third to one-half natural slate's $10 to $30 per-square-foot cost.

Historic-district status favors natural slate when the home already carries slate or sits in a designated local historic district, where Standard 6 of the Secretary of the Interior's Standards directs an in-kind match rather than an asphalt substitute. A partial asphalt swap on a contributing structure can require a Certificate of Appropriateness; below 20% slate failure, NPS Preservation Brief 29 favors selective slate repair over a roof replacement in a different material. The federal 20% Historic Rehabilitation Tax Credit and the NJ Historic Property Reinvestment Program apply only to income-producing properties, so an owner-occupied home does not qualify, per the NPS and the NJ DEP Historic Preservation Office.