Torch On Felt Flat Roof Guide Service

A properly installed, multi-layer torch on felt flat roof in Brooklyn can realistically give you 20-25 years-but a rushed, single-layer “burn and go” job might fail in under 5. The difference isn’t the roll brand or even the torch; it’s following a proper torch on felt flat roof guide that treats the system as a full assembly: substrate prep, base sheet, interply lap control, granulated cap, and tight edge details. That’s what this guide covers.

I’m Vic Donnelly. I’ve been laying torch-on modified bitumen systems on Brooklyn brownstones, garages, and small commercial buildings for 23 years. I learned hot-mop on my father’s crew in Queens and shifted to torch-applied when the industry moved past kettles. This isn’t a two-minute YouTube tutorial. It’s a proper walkthrough of how torch on felt flat roofs are built as complete waterproof assemblies-and why you shouldn’t try this with a propane torch from Home Depot.

What “Torch-On Felt” Actually Means (Not Just Heating Something Until It Sticks)

Torch-on felt is shorthand for torch-applied modified bitumen roofing. You’re not torching old-style organic felt. You’re heating rolls of factory-made membrane-SBS-modified bitumen reinforced with fiberglass or polyester-until the bottom surface melts and bonds to the substrate or the layer below. Done correctly, you build up multiple plies with controlled overlaps to create a redundant, fully adhered waterproof system.

The key components:

• Deck: Timber, concrete, or other structural base
• Primer: On porous or dusty surfaces to promote adhesion
• Base sheet / underlay: First membrane layer, smooth or lightly granulated
• Cap sheet: Top layer with ceramic granules for UV and foot traffic resistance
• Edge and upstand details: Drip edges, parapet flashings, pipe collars, corner reinforcements

Most failures I see in Brooklyn happen at terminations, corners, and penetrations-not in the middle of the roof. That’s why treating this as an assembly, not a surface, is the entire point of a proper torch on felt flat roof guide.

Is Torch-On Right for Your Brooklyn Roof?

On a Park Slope rear extension we reroofed last fall, the owner asked if torch-on was “old-school” compared to TPO or EPDM. My answer: it’s not old-school-it’s proven. Torch-on excels on smaller residential roofs with complex edges, parapets, and party walls. It handles Brooklyn’s freeze-thaw cycles, adapts to uneven masonry upstands, and repairs well.

Torch-on felt makes sense if:

• You have a straightforward flat roof, garage, or extension under 2,000 square feet
• You want a multi-ply system with redundancy and a granulated, walkable surface
• Your structure is sound, can handle the weight (roughly 200-250 lbs per 100 sq ft), and you have safe access for materials
• You’re hiring a contractor who respects fire safety and knows proper lap sequencing

Where torch-on is not the best fit:

• Very large commercial roofs where single-ply makes more economic sense
• Structures with severe access limitations or fire separation concerns
• Roofs with poor drainage where ponding is chronic (fix falls first)
• DIY scenarios-this is not a weekend project with YouTube and a borrowed torch

Step 1: Inspection and Planning-Before Any Flame Touches Anything

On a Bay Ridge garage we rebuilt last summer, the owner wanted to “just put new felt over the old.” When we pulled samples, we found three previous layers, wet OSB underneath, and rafters sagging half an inch. We stripped everything, sistered new framing, added tapered sleepers for positive drainage, and then built a proper two-ply system. The planning phase saved that roof.

Questions we answer during inspection:

• What is the deck material, and is it structurally sound and dry?
• How does water drain-gravity, scuppers, internal drains-and are there ponding zones?
• What is the current build-up height relative to doors, windows, and parapet caps?
• How many old roof layers exist, and do they need removal?
• Are there fire exposures-party walls, wood siding, nearby openings-that affect torch use or require cold-applied alternates?

From that, we design the system: number of plies, insulation upgrades, fall corrections, edge and penetration details. This planning is the “guide” in our guide service.

Step 2: The Correct Layer Build-Up for a Torch-On Felt Flat Roof

Here’s the sequence for a typical warm-roof assembly on a Brooklyn residential roof, from inside to outside:

Most torch-on felt failures happen at terminations, corners, and penetrations-not in the middle. Our guide service focuses heavily on how the layers turn up at parapets, tie into existing walls, and wrap around pipes and skylights to keep those spots dry.

Why Torch-On Felt Is Absolutely Not a DIY Project

You can understand the process without doing the dangerous part. Watching videos of torch-on installations makes it look straightforward: roll, heat, stick. In reality, controlling heat, avoiding hidden hot spots, judging proper bonding, and managing open flame near combustible walls all take experience-and mistakes can mean fire, fumes, and leaks that only show up later.

What homeowners can safely do:

• Decide on goals: lifespan, insulation upgrade, future deck or not
• Clear access and interior spaces below the work area
• Discuss drainage preferences (where water should exit, away from neighbors/doors)
• Review and approve the system design and any visible trims or finishes

What we, as torch-on specialists, handle:

• All torch work, including safe burner operation and heat control
• Deck assessment and replacement where rot or sagging is found
• Slope corrections and integration with existing drains and scuppers
• Detailed upstands, corner work, and tie-ins at party walls and parapets
• Fire watch, flame shields, and compliance with NYC/FDNY torch-roofing guidelines

Torch Safety and NYC Compliance on Residential Brooklyn Roofs

On a Crown Heights multi-family we reroofed two years ago, the existing roof was three feet from a wood-sided neighbor and six feet from an open stairwell skylight. We used flame shields at the party wall, switched to cold-applied adhesive for the upstand details on the neighbor side, kept charged hoses and extinguishers on hand, and maintained a dedicated fire watch during and after all torch work. No shortcuts.

Key fire-safety measures built into every torch-on project:

• Flame shields and non-combustible protection at wall bases and around penetrations
• Limiting open flame near combustible walls, siding, and old timber framing
• Fire extinguishers and charged hoses on hand, with a designated fire watch during and after torching
• Following NYC/FDNY guidelines for torch-applied roofing work

Permits and coordination: Depending on scope, replacing or upgrading a flat roof-especially if adding insulation or changing drainage-can involve DOB permits, energy code considerations, and sometimes landmark or co-op/condo board approvals. Our role is to coordinate our work with your architect and expeditor so torched felt installation fits into a compliant project.

Common Torch-On Felt Contractor and DIY Red Flags

I’ve seen a lot of bad torch work in Brooklyn. Here’s what “wrong” looks like-and what you should watch for:

• Torching over wet wood: Steam pockets will form under the membrane and cause blistering within months.
• Skipping the base sheet: A single-ply cap sheet has no redundancy. If one nail or seam fails, you leak.
• Tiny lap overlaps (under 3″ side, under 6″ end): Water will wick through under pressure or freeze-thaw cycling.
• No granulated cap at the surface: Smooth base sheets exposed to UV degrade fast and become slippery and fragile.
• Open corners and fishmouth ends: Edges that aren’t cut, sealed, and torched flat will lift and let water in.
• Working too close to siding or parapets without protection: Charred wood, melted vinyl, cracked masonry-I’ve seen it all from careless torch use.

A proper torch on felt flat roof has neat, consistent laps with visible bitumen bleed-out (a thin dark line at the seam edge showing full melt and bond), tight corners, and clean upstands that integrate with metal or masonry flashings. If it looks rushed or patchy, it probably is.

Maintaining and Repairing a Torch-On Felt Roof

On a well-drained, properly detailed roof, a good-quality multi-layer torch-on felt system can last 15-25 years or more in Brooklyn. Lifespan depends heavily on exposure, foot traffic, drainage, and maintenance.

Basic care for torch-on felt roofs:

• Keep drains, scuppers, and gutters clear of leaves and debris
• Have seams and details checked every 3-5 years, especially after big storms or heavy snow seasons
• Repair localized damage with compatible torch-on materials-new patches or flashing work-rather than generic tars or roof cement
• Avoid dragging furniture, planters, or equipment directly across the surface; use pads or pavers where traffic is regular

Repairs are straightforward when done right: clean the area, cut a patch with generous overlap, torch it into place with full perimeter sealing, and detail the edges. Done badly-slapping cold tar over granules-repairs fail fast.

Torch-On Felt Flat Roof – Common Questions

Is torch-on felt safe for old Brooklyn buildings?
It can be when installed with strict fire-safety controls and experienced crews. We use flame shields, limit torch use near combustible walls, maintain fire watch, and sometimes switch to cold-applied methods at particularly sensitive areas.

Is torch-on felt better than EPDM or TPO?
It depends. Torch-on excels on smaller, more detailed roofs with parapets and masonry, and where a granular, walkable surface is desired. EPDM or TPO may be better on larger, simpler roofs or where low weight and reflectivity are top priorities. We guide you through that choice based on your building.

Can you install torch-on felt over my existing roof?
Sometimes. If the existing roof is sound, dry, and not already over-layered, a new system can be applied over it with proper prep and detailing. If there are multiple layers, trapped moisture, or structural concerns, we strip down to a solid base first.

Will a torch-on felt roof work under a deck or roof terrace?
Yes, with the right protection. We typically install the torch-on system, then add separation layers and pavers or decking on supports. That keeps the membrane protected from wear and makes future inspections and repairs easier.

How is your torch-on felt guide service different from a normal roofing quote?
Instead of jumping straight to “we’ll torch a new roof on,” we start with inspection, discuss your goals (lifespan, insulation, deck use), explain system options, and walk you through the layer build-up and details specific to your roof-so you understand what you’re buying and why.

Need a Guided Torch-On Felt Flat Roof Project in Brooklyn?

Our torch-on felt flat roof guide service includes:

• On-site assessment of your existing roof, structure, and drainage
• Recommendations on whether torch-on felt is right for your home or if another system fits better
• A clear, step-by-step plan for stripping, rebuilding falls, and installing the felt system
• Safe, code-conscious torch-on installation customized to Brooklyn building conditions

Ready to talk through a torch-on felt solution for your flat roof?

We’ve installed and replaced torch-on felt roofs on Brooklyn garages, rear extensions, and small building roofs for years. Our goal is to pair the right system with careful design and safe installation-so your new roof is something you don’t have to think about every time it rains. Contact FlatTop Brooklyn for a consultation and let’s walk your roof together.