Commercial Flat Roof Beyond Repair? Need a new Flat Roof?
When Patching Is No Longer Enough — GenSun Delivers a Complete, Reliable Commercial Flat Roof Replacement.
- 35 years in business
- Insured and Certified
- 5 Star Google rated
- Easy online estimate meeting
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Licensed & Insured | Free Inspections | Local for 3 decades | 
Google Rated
When Does Your Commercial Roof Need Full Replacement?
While roof coatings can extend the life of a sound roof, some roofs have deteriorated beyond the point of repair. A complete commercial roof replacement is the right solution when structural integrity is compromised and long-term protection of your building and assets is the priority.
💰 The Value of Investing in a Full Roof Replacement
Full Replacement
$9–$16*
per square foot
Brand new 25–30 year roof system Full tear-off & disposal included New insulation & membrane Manufacturer warranty included Maximizes property value Eliminates all existing damage
* 10-20% Lower than any other quality roofer, there pricing is $14-$25per sf
Endless Patching
Costly
& Temporary
❌ Repairs only mask deeper damage
❌ Costs accumulate year after year
❌ Interior water damage risk grows
❌ No warranty protection
❌ Reduces property value
❌ Never truly solves the problem
💡 A new roof can increase your property value by 5–10% and eliminate costly interior damage caused by prolonged leaks.
Commercial Roof Replacement Systems We Install
⬛ TPO (Thermoplastic Polyolefin)
Best For: Flat & low-slope commercial roofs
Lifespan: 20–30 years
Benefits: Highly reflective white membrane dramatically reduces cooling costs. Heat-welded seams create a watertight bond. Excellent resistance to UV, ozone, and chemical exposure. One of the most popular commercial roofing systems in the Northeast.
EPDM (Rubber Membrane)
Best For: Large flat commercial roofs
Lifespan: 25–30 years
Benefits: Exceptional durability in freeze-thaw conditions — ideal for winters. Lightweight, cost-effective, and straightforward to repair if punctured. Proven 30+ year track record in commercial roofing applications throughout the Northeast.
⬛ Modified Bitumen
Best For: Low-slope roofs requiring superior durability
Lifespan: 20–30 years
Benefits: Multi-ply reinforced system provides outstanding puncture and tear resistance. Excellent performance in extreme temperature swings — critical for NJ winters. Can be torch-applied, cold-applied, or self-adhered. Outstanding impact resistance and long-term flexibility.
🏗️ Why Proper Insulation & Roof Pitch Are Critical
A new roof membrane alone is not enough. The two most overlooked — and most costly — mistakes in commercial roofing are inadequate insulation and improper roof pitch. At GenSun, every replacement addresses both from the ground up.
🧱 Proper Roof Insulation
Insulation is the engine of your roof’s energy performance. Without proper insulation, your HVAC system works overtime year-round — driving up operating costs and reducing your building’s comfort and efficiency.
Why It Matters:
- Reduces heating & cooling costs by up to 40%
- Prevents condensation buildup that rots roof decking from within
- Provides structural support for the membrane system above
- Minimizes thermal bridging that accelerates material degradation
- Required to meet current NJ energy code standards
- Polyisocyanurate (Polyiso) foam board is the most common and efficient commercial insulation — delivering an R-value of 6.5 per inch
⚠️ Warning: Wet or compressed insulation loses up to 70% of its R-value. During a replacement, all saturated insulation must be removed and replaced — not covered over.
📐 Proper Roof Pitch & Drainage
Standing water is the single greatest enemy of any commercial roof. Even a perfectly installed membrane will fail prematurely if water has nowhere to go. Proper roof pitch ensures every drop of water drains off quickly and completely.
Why It Matters:
- The minimum recommended slope for commercial roofs is ¼ inch per foot
- Ponding water (standing 48+ hours) accelerates membrane breakdown
- Adds hundreds of pounds of load stress to the roof structure
- Promotes algae, mold, and biological growth that degrades materials
- Tapered insulation systems can correct flat spots and low areas without adding structural load
- Properly designed internal drains, scuppers, and gutters must be sized for local rainfall intensity
⚠️ Warning: Many commercial roofs in NJ were built with insufficient slope. A full replacement is the ideal opportunity to correct pitch issues using tapered insulation — solving the drainage problem permanently.
🏆 GenSun addresses insulation, pitch, drainage, AND membrane in every replacement — because a roof is only as good as the system beneath it.
Commercial Roof Systems — Lifespan & Investment Comparison
We are 10%-20% Lower than any other quality roofer
| Roof System | Lifespan | Cost / Sq Ft | Energy Savings | Warranty |
|---|---|---|---|---|
| TPO | 20–30 years | $9–$16 | Up to 30% | 15–20 yr manufacturer |
| EPDM | 25–30 years | $9-$16 | Up to 15% | 10–20 yr manufacturer |
| Modified Bitumen | 20–30 years | $9-$16 | Up to 20% | 10–20 yr manufacturer |
| Metal Roof | 30–50 years | $20-$30 | Up to 40% | 30–50 yr manufacturer |
| Ongoing Patching | 1–3 years per patch | Accumulates rapidly | None | No warranty |
Rated 5 Stars on Google
Trusted by Commercial Property Owners for over 3 decades
What Our Clients Are Saying about
“Tremendous job by there crew. Very happy we resolved the never ending repair cycle we incurred….ty, GenSun and Coach Jim for being hones, straightforward and very easy to obtain an estimate online”
— Jake Daniels, Industrial building
“They explained the installation process better than any other roofer we met with, it was obvious they know what they are doing. I can’t say enough about the easy online process of getting an estimate with out the hassles of the dog and pony show that the other roofers wanted to do on top of the roof”
— Muhammad, Commercial bldg
“We met with 5 roofers and GenSun was the easiest to work with. they explained all options and even gave us a quick quote for all options…no secrecy, no need to meet on top of the roof, just a low price. After I liked there price, they sent a person to do an inspection and they even lowered the price after the inspection…so honest!”
— Ira Goldstein, Office building
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Your Building Deserves a Roof That Lasts 25–30 Years
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GenSun Commercial Roofs | Bergen & Passaic County, NJ | Licensed & Insured | gensunroofingnj.com