Modified Bitumen Roofing in Queens, NY

Modified bitumen is what most New Yorkers call a torch down roof. It's the layered, asphalt-based flat roof you see on rowhouses, apartment buildings and garages all over the boroughs, with the gray granules on top. I'm Stavros Latos, owner of REVMA Roofing in Bayside, and when a flat roof gets walked on, has equipment on it or has old parapet walls to tie into, mod bit is usually the system I recommend.

What Modified Bitumen (Torch Down) Roofing Is

Bitumen is asphalt. "Modified" means it's mixed with rubber or plastic polymers so it stays flexible in the cold and doesn't go soft in the heat. It comes in rolls with a reinforcing mat inside, and it goes on in two layers: a base sheet, then a cap sheet with granules that protect it from the sun and take the foot traffic.

"Torch down" is just one way of putting it on. The installer heats the back of the roll with a torch so the asphalt melts and bonds to the layer below. Mod bit can also go on cold, with adhesive, or as a self-adhered peel-and-stick sheet, and on tight rowhouse roofs next to old wood that's sometimes the smarter choice.

How We Install a Modified Bitumen Roof

Same as every REVMA roof, we strip it down to the deck and do it from scratch. Then:

• Deck repair. Three to five sheets of plywood included, and I show you pictures of anything beyond that before we replace it.
• Drainage. Tapered insulation or crickets so water moves to the drain or scupper.
• Insulation and cover board so the system has a solid, flat base.
• Base sheet, then the granulated cap sheet, with the laps staggered and every lap sealed the full width.
• Parapets and party walls. The membrane runs up the wall and gets capped and counter-flashed so water can't get behind it.
• Drains, scuppers, vents and hatches flashed one by one, with new drain bodies where the old ones are rusted.
• Metal edge or coping, cleanup and a magnet sweep.

When any part of the job is torch-applied, FDNY requires a Certificate of Fitness holder on site, and we keep fire safety in the plan from the first day, including where the torch goes near wood and how we check the roof before we leave.

Is Torch Down Roofing Good? When Mod Bit Is the Right Pick

For a lot of NYC flat roofs, yes. Two layers with a granulated top is a tough roof. It handles foot traffic, AC condensers and the guy who comes to service them, and it ties into old brick parapets well. That's why so many apartment buildings and rowhouses have it.

Where it's not the best pick: if the room under the roof runs hot in summer, a white TPO roof will keep it cooler. If you want the simplest roof to patch later and nobody walks up there, EPDM rubber is hard to beat. I'll tell you which one I'd put on your house after I've been up there, and all three are compared on our flat roofing page.

Common Problems With Modified Bitumen Roofs

Most mod bit problems I see come down to three things, and none of them are the material's fault:

• Laps that weren't sealed. If the seam wasn't heated or glued the full width, it opens up and water gets in between the layers.
• Blisters. Moisture or air trapped under the sheet when it went down expands in the sun and lifts the membrane.
• Ponding. Water that sits wears out the granules and the seams in that spot first.

Let's say your roof has blisters all over and a puddle that never dries in the middle. Cutting and patching the blisters doesn't fix the drainage, so at that point you're paying for a patch every year. You get what you pay for at the end of the day, and doing it once the right way costs less than doing it twice.

Modified Bitumen Roof Cost in Queens

Flat roofs run about $900 to $1,400 a square installed in Queens, and a typical 8 to 12 square rowhouse rear roof comes in around $8,000 to $16,000. On a mod bit roof the number moves with how many layers we tear off, how much plywood is rotten, how much tapered insulation it takes, and how much parapet and drain work there is.

You get one written price after I've been on the roof, and with no big-company overhead it usually comes in 25 to 35% less than the big companies for the same system. Got a written quote for the same roofing system from somebody else? Show me and I'll match it. For the bigger picture: how much a new roof costs in Queens.

Torch Down Roofs on Attached Homes

On attached and semi-attached houses, your roof runs into your neighbor's. We tie in at the party wall, flash it so the joint can't leak into either house, and let the neighbor know before we start. Access is usually through the house or over the front, so the protection and the debris route are planned before I give you the price.

Where We Install Modified Bitumen Roofs

We're based in Bayside and we work Queens, the Bronx and Staten Island. That covers Bayside, Whitestone, Flushing, Douglaston and Little Neck, and Astoria, Jackson Heights, Forest Hills and Jamaica further in.

Modified Bitumen and Torch Down Questions