Why Flat Roofs Are Everywhere on LI
Long Island is full of flat roofs. Ranch-style home additions built in the 1960s and 70s. Attached garage extensions. Sunroom conversions. Commercial strip malls along every major road from Hempstead Turnpike to Route 110. Multi-family buildings in Bay Shore, Patchogue, and Hempstead.
Flat roofs are not actually flat. They have a slight slope (typically 1/4" per foot) to move water toward drains or scuppers. When that slope fails, when seams open, when the membrane cracks, water ponds and finds its way inside. We fix that.
Flat Roof Systems We Install
TPO (Thermoplastic Polyolefin)
Our most-installed flat roof membrane. TPO is white, reflective (reduces cooling costs), and heat-welded at the seams for a waterproof bond. We install 60-mil and 80-mil TPO from GAF, Carlisle, and Firestone.
Best for: Residential additions, commercial buildings, any flat roof where energy efficiency matters Lifespan: 20-30 years Cost: $8-$14 per sqft installed
EPDM (Rubber)
The traditional rubber roof. EPDM is a proven membrane that has been protecting flat roofs for 50 years. It is less reflective than TPO but extremely durable and flexible in cold weather. We install 60-mil EPDM from Carlisle and Firestone.
Best for: Budget-conscious projects, northern-exposure roofs, cold climate flexibility Lifespan: 20-25 years Cost: $7.50-$11 per sqft installed
Modified Bitumen (Mod-Bit)
A multi-layer torch-applied or cold-adhesive system. Modified bitumen is heavier and more puncture-resistant than single-ply membranes. We use it on flat roofs that get foot traffic (rooftop HVAC access, rooftop decks) or where puncture risk is high.
Best for: Commercial roofs with HVAC equipment, rooftop access areas, high-traffic flat roofs Lifespan: 15-20 years Cost: $8.50-$13 per sqft installed
Common Flat Roof Repairs on Long Island
Seam failure. The number one flat roof leak. Old seams open up over time due to thermal cycling. We clean, prime, and re-weld (TPO) or re-seal (EPDM) the failed seam.
Ponding water. Water that sits for 48+ hours after rain is ponding. It accelerates membrane deterioration and adds structural load. We correct the slope with tapered insulation or cricket builds.
Punctures. HVAC techs stepping through old membrane, falling debris, or foot traffic. We patch with matching membrane material and reinforcement.
Flashing failure. Where the flat roof meets a parapet wall, a drain, or a penetration. We strip and replace the flashing with new membrane and termination bars.
Drain and scupper clogs. We clear the debris and install new drain baskets if the old ones are missing or damaged.
Flat Roof Pricing for Long Island
| System | Price per sqft | Typical 1,000 sqft |
|---|---|---|
| TPO 60-mil | $8.00 - $12.00 | $8,000 - $12,000 |
| TPO 80-mil | $10.00 - $14.00 | $10,000 - $14,000 |
| EPDM 60-mil | $7.50 - $11.00 | $7,500 - $11,000 |
| Modified bitumen | $8.50 - $13.00 | $8,500 - $13,000 |
| Flat roof repair (seam, patch, flashing) | — | $450 - $2,500 |
Pricing includes tear-off of old membrane, new insulation where needed, new membrane, all flashings, drains, and our workmanship warranty.
