Flat Roof Replacement Cost in NJ

Price ranges for flat roofs

Researched New Jersey market ranges, gathered from published contractor price guides and national cost surveys in October 2026. They are not our quote: your price comes from a free on-site estimate, and we will replace these ranges with our own rates.

• Flat / low-slope roof replacement (EPDM, TPO, mod-bit), installed: $3 to $14 per square foot, typically about $7

Size and the per-foot price

Small roofs over porches and dormers usually cost more per square foot than large roofs, because setup, edge metal and flashing are spread over fewer feet. A small porch roof may land near $14 per square foot even with a simple membrane, while a large open roof with few penetrations can come in close to $3. Most residential low-slope sections fall around the $7 typical figure.

Membrane, insulation and tear-off

The membrane itself is one piece of the price. TPO, EPDM, PVC and fleece-backed systems differ in material cost and in how they are attached. Removing the old roof, especially several layers of older roofing, adds labor and disposal. Wet insulation must be replaced, and adding tapered insulation to correct ponding adds material but often pays for itself in a longer-lasting roof.

Edges, walls and penetrations

Every place the membrane turns up a wall, wraps an edge or seals around a pipe, skylight or HVAC curb takes hand work. A roof with parapet walls, scuppers and several units on it costs more per foot than an open rectangle. New edge metal and the gutter or scupper connection are part of a complete job and should be on the quote.

How to read a flat roof quote

• The membrane type and thickness, and how it is attached.
• Whether the old roof is removed, and how many layers.
• Insulation: what is replaced, and whether taper is added for slope.
• Edge metal, scuppers and the connection to gutters or drains.
• Flashing at walls, skylights, pipes and equipment curbs.
• Decking repair, priced separately if it is found.