Edge metal
Gravel stop or drip edge at the perimeter set into the membrane plies.
Flat Roofing
Modified Bitumen Roofing Mahwah, NJ
A roofer in Mahwah can install, repair or replace a modified bitumen roof, the layered asphalt membrane often called torch-down, which holds up well to foot traffic and patches easily. One call to (551) 351-0251 reaches a nearby flat roof pro.
Modified bitumen is asphalt with rubber or plastic polymers mixed in, made into reinforced rolls that go down in two or more layers. SBS sheets stay flexible in the cold and can be torched, mopped, cold-applied or self-adhered, while APP sheets are almost always torched. The layers give it toughness, which is why it holds up well on roofs that see foot traffic.
The application method is one of the first decisions on a modified bitumen job. Torching gives tight, fused laps, but the flame is a fire risk near wood decks, parapets and anything combustible. Self-adhered and cold-adhesive systems avoid the flame and are often chosen for homes and occupied buildings.
Mod bit fails in predictable ways, which helps when you call. Look for blisters, splits, granule loss and seams that curl up at the edge, and note where water stands after rain. Also mention any past coatings or cement patches, which the roofer will need to deal with.
Many modified bitumen roofing calls in Mahwah also turn up a need for flat roof replacement or flat roof repair.
Dealing with this in Mahwah, NJ right now? Call (551) 351-0251 and describe the problem to a roofer who works in Mahwah.
Call nowThe process
How a modified bitumen roof is installed
Here is how a typical modified bitumen job runs.
Start with the deck
A core cut and a walk of the roof show how many layers exist and whether moisture is trapped. With two roofs already in place or wet insulation present, a tear-off is the norm.
Tear off old roofing
On a tear-off, everything comes down to the deck and damaged plywood or planks are replaced. Insulation or a cover board is added, with tapered sections where water needs help reaching the drains.
Install the base ply
The first ply is nailed or mechanically fastened on wood, or set in adhesive over insulation. Its laps are staggered from the cap sheet laps to avoid weak lines.
Install the cap
A cap sheet with mineral granules is applied over the base sheet. On torched laps, a steady bleed-out of asphalt at the edge shows a good seal.
Flash the details
Parapets and curbs are flashed with mod bit plies, then capped or counterflashed with metal. New drip edge or gravel stop and properly set drain flashings finish the edges.
Keep a fire watch
After torch work, a fire watch confirms no hidden heat remains in insulation or wood. The roofer also confirms that drains are clear and the roof sheds water.
What is included
Parts of a modified bitumen roof
Base flashing
Flashing that runs up the wall and under metal so wall joints stay dry.
Base sheet
A smooth reinforced base sheet laid with laps offset from the cap.
Granulated cap
A top ply surfaced with mineral granules to shield the asphalt from sun.
Tapered insulation
New insulation where the roof is torn off built to current code levels.
Related service
Torch Down Roof Repair Mahwah, NJ
Repairing a torch-down roof usually means cutting out the bad section and fusing new modified bitumen over it. A blister is cut in an X or cut out, the area is dried and sealed, and a new piece of cap sheet goes over it. Loose granules are embedded in the bleed-out so the patch does not weather quickly.
In Mahwah, many torch-down repairs sit close to wood framing, so fire safety is part of every job. Near combustible materials, a cold-process or peel-and-stick patch can replace torching. After torching, a watch period for smoldering material is standard practice.
Related service
Built Up Roofing Mahwah, NJ
Built up roofing stacks three or more plies of felt and bitumen into a thick, heavy membrane, finished with a layer of gravel. The gravel protects the bitumen from sun and foot traffic, so bare spots where it has blown or washed away are a common source of trouble. These roofs can last a long time, but blisters, splits and failed flashings show up as they age.
Repairs on a built up roof in Mahwah usually involve scraping back the gravel, patching with felt and bitumen or modified bitumen, and replacing the gravel. When a built up roof reaches the end of its life, its weight and the gravel usually mean a tear-off before the new roof goes on. The replacement is often a mod bit or single-ply roof that is lighter and easier to maintain.
Local help
Modified Bitumen Roofing Near Me
Around Mahwah, mod bit replaced a lot of old tar and gravel roofs years ago, and many of those are now due for work. Across Mahwah and nearby towns like Ramsey, Allendale, Ringwood and Oakland, older buildings may still have built-up roofs under a layer of mod bit, which is why the core cut matters, and the first step is finding out how many layers are already on the deck.
Need modified bitumen roofing around Mahwah? Call (551) 351-0251 for a Mahwah roofer who serves the towns around it too.
Roofs in this climate
Cold winters bring snow, ice and a long stretch of freezing nights. Heat escaping from the attic melts snow on the upper roof, and the water refreezes at the colder eaves, which is how ice dams form and back water up under the shingles. Strong coastal storms push rain into every weak spot at the flashing and valleys. Most homeowners in Mahwah, NJ have the roof checked in the fall and again after the snow melts.
Why call
Why fix it now
Less damage
Small roof problems caught early usually stay small repairs.
Roofers who know Mahwah
Local roofers see the same roofs and storm damage across Mahwah and nearby towns.
Know what happens next
Ask the roofer about the cause, the options and the estimate before work starts.
Modified Bitumen Roofing questions
How long does a modified bitumen roof last?
A two-ply modified bitumen roof commonly lasts around 15 to 25 years. Good drainage, intact granules and sound flashings push it toward the long end. A reflective coating applied before the cap sheet wears out can extend its life.
Is torch-down roofing safe?
Fire risk with torch-down comes from the flame during installation, not the finished roof. Safe practice includes not torching directly on wood, keeping extinguishers on the roof and watching for smoldering after the flame is off. On homes, self-adhered or cold-applied modified bitumen avoids the flame entirely.
What is the difference between modified bitumen and built up roofing?
The two are related, with key differences in material and installation. Built up roofs stack felts and hot bitumen with gravel on top, and mod bit uses two or three factory-made sheets with granules. Mod bit is lighter and more flexible, which is why it has replaced built up roofing on many buildings.
Can modified bitumen be installed over an existing roof?
The core cut tells the roofer. If there is a single, dry, sound roof, a recovery board and new mod bit may go over it. If there are already two roofs, blistering throughout or wet insulation, a tear-off is the right move.
Can a mod bit roof be coated?
Coating an aging cap sheet is a common way to add years to a mod bit roof. Loose granules are cleaned off, blisters and open laps are repaired and a primer may be needed to keep asphalt from bleeding through. White coatings reflect sun, which helps the asphalt last.
More questions? Call (551) 351-0251
Often needed together
Flat Roof Replacement
Tearing off or recovering a worn flat roof and installing a new membrane, insulation and edge metal, and new flashing at every wall, curb and drain.
Learn moreFlat Roof Repair
Flat roof repairs matched to the membrane, whether EPDM, TPO, PVC, modified bitumen or built-up, with the patch made from material that bonds to what is there.
Learn moreTPO Roofing
TPO membrane roofs installed over new insulation or in place of a worn flat roof, built around proper drainage, flashing and edge metal.
Learn moreCommercial Roof Replacement
Tear-off or recover of aging commercial roofs with new insulation and drainage, planned around rooftop units and drains.
Learn more
Looking for something else?
See all roofing servicesTalk to a Mahwah roofer about modified bitumen roofing
Call (551) 351-0251 to talk to a roofer serving Mahwah, NJ.