Flat roof repair and replacement on Staten Island, fixed at the cause
Most Staten Island flat roofs sit over a rear extension, a garage or an attached townhouse, and most of them leak for the same few reasons. We find yours, fix it properly, and tell you straight whether a repair will hold or the roof is done.
- EPDM, TPO, PVC and modified bitumen, repaired or replaced
- Hidden leaks and wet insulation found with infrared cameras
- Drainage fixed so water stops sitting on the roof
- Written estimate, usually within 24 hours
- 5.0 from 154 reviews
GAF Master Elite®- Lic. #2129904-DCWP
Get your free roof estimate
Step 1 of 3Takes 30 seconds. A real person from our team calls you back, usually within the hour.
A new flat roof on Staten Island costs about $5,000–$13,000 for a typical 1,000 sq ft roof. By system: EPDM $5–$12 per sq ft, TPO $9–$14, modified bitumen $9–$13 and PVC $10–$16. Most flat roof leak repairs cost $400–$1,200. Repair if the roof is under about 15 years old and the problem is in one spot.
- Infrared leak detectionHidden moisture found, no guesswork
- Written price in 24 hoursItemized, no pressure
- Most roofs done in 1 dayTear-off to cleanup
- Up to 50-yr warrantyPlus 25 yrs on workmanship
Why Staten Island flat roofs leak
Flat roofs don't fail at random. On Staten Island homes, almost every leak we trace starts in one of five places:
- Seamsthat have opened or lifted on rubber or TPO
- Flashingwhere the roof meets the house wall, a parapet or a chimney
- Drains and scuppersclogged with leaves, so water sits and finds a way in
- Penetrationslike vent pipes, exhaust fans and AC lines
- Blisters and splitsin older modified bitumen or tar roofs
Salt air and wind near the water in South Beach, Midland Beach and Great Kills, and freeze-thaw cycles all winter, speed all of this up. Water can travel a long way under a flat roof before it shows up inside, so we scan the roof with an infrared (thermal imaging) camera to see where wet insulation is hiding. We find the real entry point, which is often several feet from the stain on your ceiling, and repair it with materials that match your existing roof. Most of these repairs cost $400–$1,200. See our full roof leak repair cost guide for more detail.
Water coming in right now? Call our 24/7 emergency line at (929) 370-1552.
Flat roof systems we install
EPDM (rubber)
$5–$12 per sq ft. The best value for most home extensions and garages. Stays flexible through cold winters.
TPO
$9–$14 per sq ft. A white, heat-welded membrane that reflects sun and keeps the room underneath cooler. See our TPO roofing guide.
Modified bitumen
$9–$13 per sq ft. Multi-layer roofing that stands up to foot traffic, roof decks and AC units.
PVC
$10–$16 per sq ft. Resists grease and chemicals. Mostly used on restaurants and commercial roofs.
Repair or replace? The honest answer
Repair if the roof is under about 15 years old, the problem is in one area, and the membrane is still flexible.
Replace if the roof is near or past 20 years, the insulation underneath is wet over large areas, it leaks in more than one place, or you've already paid for the same repair twice.
When it's close, we give you both prices and photos of what we found, so you can decide with real numbers. Our guide to flat roof repair vs. replacement goes deeper, and the roof replacement cost guide breaks down full-roof prices.
What homeowners ask before they call
Will it be a mess?
We protect your yard, windows and AC units, haul away every scrap, and sweep for nails before we leave.
Do I need a permit?
Sometimes. We check what applies to your house, including NYC cool-roof rules, and file when it's required.
Are you insured?
Yes. Licensed by NYC DCWP (#2129904-DCWP) and fully insured. Ask and we'll send proof.
Who does the work?
Our own crew, not subcontractors. Owner Marke is part of every job.
Why Staten Island homeowners choose us
Alter Phase Roofing Contracting is a family-owned roofer based on Staten Island, with 19+ years in roofing. We're a GAF Master Elite® contractor, BBB Accredited, and rated 5.0 stars across 154 reviews, 109 of them on Google. New flat roofs come with up to 50-year manufacturer and up to 25-year workmanship warranties, in writing.
We work on flat roofs in every neighborhood, from St. George and Rosebank to New Dorp, Eltingville and Tottenville. For stores and larger buildings, see commercial roofing.
Next step: call or text (929) 370-1552 for a free inspection with photos. You'll usually have a written estimate within 24 hours.
What flat roofing costs on Staten Island
Averages from our own jobs. Your exact price comes in writing after a free inspection.
New flat roof, installed · Staten Island
Flat roof replacement by borough (≈1,000 sq ft)
Alter Phase Roofing Contracting job averages, updated October 26, 2026. Your exact price comes from a free on-site inspection.
- Tear-off, cleanup and disposal
- Up to 50-yr material + 25-yr workmanship warranty
- Permit filed if your job needs one
Final price depends on layers to remove, deck condition and access. We confirm it in writing after a free inspection.
Get my exact price, free or call (929) 370-1552Might only need a repair? Most roof repairs cost $300–$1,200. We'll tell you honestly. Roof repair
From first call to finished roof.
No pushy salespeople and no surprise bills. Every job follows the same four steps.
- Fast scheduling
We inspect your roof
We climb up, scan for hidden leaks with an infrared camera, find the real cause and take photos so you see exactly what we see.
- Within 24 hours
You get a written quote
Clear options, repair or replace, with materials, cleanup and permits itemized. No pressure.
- On your schedule
Our own crew does the work
Marke is part of every job. We protect your property and clean up every day.
- Final walkthrough
Warranty in writing
Up to 50 years on materials and up to 25 years on our workmanship, handed to you.
What Staten Island customers say
“10/10 would recommend! This is the second time I've used this company, and they've been excellent both times. The first time was a few years ago for a full shingle replacement. Most recently, I called them back to repair my flat roof and gutter system after a rough winter caused pooling and a leak. They came out the very next day to assess the issue, which I really appreciated. The team was professional, polite, and their pricing was extremely fair. Because of the weather, the job required multiple visits but their communication was consistent, clear, and reliable throughout. They always showed up exactly when they said they would, which is rare these days. It's hard to find a trustworthy company for major home repairs, especially when so many are overpriced and underdeliver. This team exceeded expectations, and I'll absolutely continue to use them in the future.”
“Alter Phase Roofing Contracting is a very good company. My new roof they installed just in one day, very professional and responsive. Clean very nice after the job and very friendly. The new roof has withstood several heavy rainstorms without any leaks. They are very respectful to come back inspected whole roof to make sure no any…”
“Quick, reliable and does OUTSTANDING work. We had a leak on our roof and made calls and left messages. They were the only company that called me back with in 10 min, they gave me an appointment the same day to come out and check out our roof. When we agreed to use them they were back here in 2 days to replace the roof and did an…”
“The roofing job was completed with exceptional skill and professionalism. The team arrived promptly and conducted a thorough assessment of the roof's condition, identifying areas that required repair. They replaced damaged shingles, sealed leaks, and ensured proper ventilation, all while maintaining a clean worksite, I recommend…”
“Everyone I dealt with at this company was quick to reply, professional and efficient. I reached out them one evening due to a leak in my roof. They coordinated with me immediately and made an appointment for a free quote the following morning. By the following evening, my roof was repaired. They spoke with us in morning to go over…”
“My garage roof is beautiful. I watched as Mike and crew worked, observed the great care they took in addressing every detail. I have never seen work performed with a more conscientious and professional regard. They were absolutely fastidious in the cleanup process. They even offered to make small cement repairs that they noticed…”
Flat roofing: your questions, answered
Don't see yours? Call or text and you'll talk to someone who actually works on roofs.
(929) 370-1552Flat roofing: common questions
How do you find a leak in a flat roof?
With an infrared (thermal imaging) camera. Water trapped under a flat roof membrane soaks the insulation, and wet insulation holds heat differently from dry, so it shows up clearly on the camera, usually best in the evening after a sunny day. That shows us where the water is spreading and how far, so we repair the real entry point and replace only the wet section, not more roof than you need.
What is the best flat roof material for a Staten Island home?
For most rear extensions, garages and attached homes, EPDM rubber is the best value and handles freeze-thaw winters well. TPO costs a little more, and its white surface keeps the room below cooler in summer. Modified bitumen is the toughest choice if you walk on the roof or keep equipment up there. We recommend based on your roof, not on what we have in the truck.
How much does it cost to fix a leak in a flat roof?
Most flat roof leak repairs on Staten Island cost $400 to $1,200. A single open seam or a cracked flashing is at the low end. Several problem spots, or a repair that also fixes a drain, is at the high end. You get a written price before any work starts.
How long does a flat roof last?
EPDM, TPO and modified bitumen usually last 20 to 30 years, and PVC 25 to 35 years, when installed properly and kept clear of standing water. Ponding water and skipped maintenance shorten that more than anything else.
Is water sitting on my flat roof a problem?
Yes, if it's still there about two days after rain. Standing water wears out the membrane faster and adds weight. It usually means a clogged drain or a low spot. We fix it with drain repairs or tapered insulation that pitches water off the roof.
Do I need a permit to replace a flat roof on Staten Island?
A like-for-like replacement of the roof covering on a home often doesn't need one. Changing the roof system, replacing the deck or larger buildings usually do, and full replacements can trigger NYC cool-roof rules. We check what applies to your house and file when it's required.
Get an honest answer about your roof.
Free inspection, photos of what we find and a written quote. If it only needs a repair, we'll tell you.
Prefer to talk? Call or text, emergencies 24/7:
(929) 370-1552- Family-owned, Staten Island based
- Owner on every job
- Written warranties, permits handled
Get your free roof estimate
Step 1 of 3Takes 30 seconds. A real person from our team calls you back, usually within the hour.