AFTER SERVICE / FLAT ROOF
Flat Roof Replacement
Flat roofs that drain, not pond.
Landstar replaces flat and low-slope roofs in EPDM, TPO, modified bitumen, and torch down, installing manufacturer-backed systems with proper flashing and drainage. Licensed and insured.
02 / THE SHORT ANSWER
Landstar replaces flat and low-slope roofs across New Jersey using EPDM rubber, TPO, and modified-bitumen systems, always over tapered insulation so water drains to the roof drains instead of ponding. Most residential flat-roof replacements in New Jersey run roughly $6,000 to $16,000, or about $8 to $15 per square foot installed.
03 / WHAT WE DO
Flat roofs are most of the back-house additions, garage roofs, and porch coverings we see across north Jersey. They’re also the part of the roof that fails first when the original install cheaped out, ponding water on a poorly drained deck, seams that weren’t welded right, edge metal that was caulked instead of flashed.
We install three systems, in roughly this order of preference for residential work: EPDM rubber (single-ply, long industry track record, easy to repair), TPO (white energy-efficient membrane, slightly newer technology), and modified bitumen (torch-down or self-adhered, lowest cost). For commercial decks we lean toward TPO; for residential additions we default to EPDM.
Every flat-roof replacement gets tapered ISO insulation underneath the membrane. That’s the difference between a flat roof that ponds for a week after every storm and one that drains in two hours. The membrane fails on the ponding roof in year ten; the tapered roof goes thirty.
04 / WHAT YOU GET
What the job includes.
- EPDM rubber, single-ply, fully adhered or mechanically fastened
- TPO white-membrane systems for energy reflectivity
- Modified bitumen (mod-bit) torch-down or self-adhered
- Tapered insulation to redirect water to drains and scuppers
- New drain bowls, scuppers, and edge metal
- Tie-in flashing where flat meets shingled roof
- Walk-pad installation around rooftop equipment
Typical start 3–5 days
Crew 3
Labor warranty Project-specific, in writing
Material rating EPDM / TPO / mod-bit
05 / HOW IT GOES
The process.
- Day 1
Inspect
Walk the deck, check for ponding water, soft spots, and failed seams. Photograph every penetration and drain.
- Day 1
Quote
Written scope, material spec, insulation depth, drain count, edge metal. No high-pressure sit-downs.
- Day 2
Tear-off
Old membrane and saturated insulation pulled to the deck. Deck inspected for rot, plywood replaced as needed.
- Day 3
Insulation and base
Tapered ISO insulation installed to redirect water to the drains. Cover board over the foam for a stable substrate.
- Day 4
Membrane
EPDM, TPO, or mod-bit installed to manufacturer spec. Seams heat-welded (TPO), solvent-bonded (EPDM), or torched (mod-bit).
- Day 5
Flash and test
Edge metal, drain bowls, and penetration boots flashed in. Water test every drain before we leave.
06 / RECENT WORK
Real flat roof jobs.
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07 / COMMON QUESTIONS
Flat Roof questions.
- How much does a flat roof cost in New Jersey?
- Most residential flat-roof replacements in New Jersey run roughly $6,000 to $16,000, or about $8 to $15 per square foot installed, depending on the membrane (EPDM, TPO, or modified bitumen), the deck condition, and how much tapered insulation the roof needs to drain properly. Landstar prices your roof exactly after a free inspection.
- EPDM, TPO, or modified bitumen, which one?
- EPDM is our default for residential flat sections, a long industry track record, single-ply, easy to repair. TPO is the energy-efficient option (white membrane reflects heat) and is common on commercial decks. Modified bitumen is the cheapest option but has more seams; we use it where budget is the deciding factor. We'll walk you through the trade-offs on the inspection.
- Why is my flat roof ponding water?
- Either the deck has settled or the original install didn't have tapered insulation. Either way, ponding shortens the life of any membrane by half. The fix is tapered ISO insulation that redirects water to the drains, we install it on every replacement.
- Can you patch my existing flat roof instead of replacing it?
- Sometimes. If the membrane is under 15 years old and the leak is at a known penetration or seam, a patch is the right call. If you've got widespread blistering, alligator cracking, or saturated insulation under the membrane, a patch buys six months and you've spent money twice. We'll tell you which one you're in.
- What's the warranty?
- Workmanship is warranted by Landstar and the membrane is covered separately by the manufacturer. Coverage varies by membrane and manufacturer; both warranties are project-specific and provided in writing with the contract.
FREE INSPECTION · NO PRESSURE
Need a professional estimate for roofing, chimney, siding, gutters, skylights, or exterior repairs?
Landstar Construction serves every county in New Jersey with free inspections, same-day estimates after inspection, financing options, and 24-hour emergency storm response.