Torch Down Roof Replacement in Los Angeles, CA

At 10624 Ventura Blvd, Los Angeles, CA 91604, Roof Replacement Inc completed a full torch-down roof replacement on this commercial-style flat roof property. The scope covered complete tear-off of the failed existing roofing system, substrate preparation, and installation of a new modified bitumen membrane system using Polyglass underlayment and cap sheet. The finished roof presents a clean, uniform surface with properly sealed penetrations, treated parapet walls, and addressed skylight curbs throughout.

Photos from the project’s first day show the extent of deterioration the existing roof had reached: heavily rusted metal deck panels, failed and crumbling built-up roofing material, widespread rust scaling across the substrate, and complete breakdown of any remaining waterproofing layer. Several areas showed through-rusting on the metal deck, and the parapet wall bases exhibited significant corrosion. The condition of the old roof made full replacement the only viable path forward.

Project Gallery

Tear-Off and Substrate Assessment

The crew began by stripping the existing failed roofing membrane down to the metal deck substrate. Photos clearly show the scope of what was uncovered: pervasive orange rust across the metal panels, large areas where the old bituminous material had separated and crumbled away, and sections where the deck had corroded through. Workers swept and cleaned the exposed deck surface thoroughly before any new material was laid. Where the canopy sections over the front elevation were stripped, the underlying deck showed similarly advanced rust and deterioration.

Base Sheet Installation with Polyglass Underlayment

Once the substrate was clean and prepped, the team installed Polyglass base sheet across the entire field of the roof. The black base ply, clearly branded Polyglass by Mapei on the roll packaging visible in multiple photos, was laid in parallel courses with consistent overlap spacing marked directly on the material. This layer is visible across both the main roof field and the front canopy section, providing the bonded base for the cap sheet to follow. Propane torches and torch wands were used throughout the application process.

Cap Sheet Application and Penetration Detailing

Over the base sheet, the crew installed a white granule-surfaced Polyglass cap sheet, which is visible across the completed roof field in multiple progress and completion photos. The white granule surface provides both UV reflectivity and a finished wearing surface appropriate for a flat commercial-style roof in Southern California. Around roof penetrations including multiple plumbing vents, HVAC curbs, and pipe stacks, the membrane was carefully cut, fitted, and torch-welded to create watertight transitions. A white sealant or mastic compound was applied at parapet wall bases and along the corrugated metal parapet structure to seal the flashing termination points.

Skylight Curb Work and Follow-Up Detailing

The property had multiple skylights, including a large dome-style unit and a multi-light flat curb assembly. Follow-up photos dated January 2026 show the crew returning to address the flat skylight curb, where the old flashing had failed and separated. Workers removed the deteriorated flashing material from around the curb frame, re-prepped the curb base, and integrated new Polyglass membrane into the curb flashing. The dome skylight received mastic sealant at its aluminum frame perimeter as part of the same detailing process. A tape measure visible in one photo shows the crew actively verifying dimensions at the skylight frame.

Project Details

ScopeFull tear-off of a failed built-up roofing system and replacement with a Polyglass torch-down modified bitumen system on a flat commercial-style roof, including skylight curb and penetration detailing.

ServiceTorch Down Roof Replacement

Property TypeResidential

LocationLos Angeles, CA

CompletedMarch 27, 2026

Materials UsedPolyglass modified bitumen base sheet, Polyglass white granule-surfaced cap sheet, Propane torch application equipment, White roofing mastic / sealant at parapet and flashing terminations, Metal edge and parapet wall flashing treatment, Existing metal roof deck (cleaned and retained as substrate)

Roofing in Los Angeles, CA

Los Angeles sits in a climate zone characterized by intense UV radiation, prolonged dry seasons, and periodic heavy rainfall that follows long dry spells — a combination that is particularly hard on flat roof membranes. The region’s sun exposure degrades unprotected bituminous roofing relatively quickly, making reflective cap sheets a practical choice for flat and low-slope roofs throughout the area. While rainfall totals are modest compared to other U.S. cities, the intensity of winter rain events means that any breach in a flat roof membrane can lead to significant water intrusion in a short period.

Our Service Area: Los Angeles, CA

Frequently Asked Questions

What are the signs that a flat roof needs full replacement rather than patching?

When a flat roof shows widespread membrane cracking, large areas of delamination, or significant rust and corrosion on the underlying deck, patching typically won’t hold long-term. The photos from this job illustrate a textbook case: the membrane had failed across most of its surface, and the metal deck beneath had corroded to the point where spot repairs would not have addressed the underlying problem. If leaks are recurring in multiple locations and the membrane is brittle or coming away from the substrate, a full tear-off and replacement is usually the more cost-effective solution over time.

How does torch-down roofing work, and why is it used on flat roofs?

Torch-down roofing, also called modified bitumen membrane roofing, uses a propane torch to heat the underside of prefabricated bitumen rolls, melting the material so it bonds directly and continuously to the layer beneath it. This creates a seamless, waterproof surface without relying on fasteners or adhesives that can fail at seams. It is well-suited for flat and low-slope roofs because the fused seams leave few mechanical attachment points for water to find its way through. The system typically involves a base sheet layer followed by a granule-surfaced cap sheet as the weather-facing layer.

Do I need a permit for a roof replacement in the City of Los Angeles?

In most cases, yes — the City of Los Angeles requires a roofing permit for full roof replacements, and requirements can vary depending on the scope of work, the property type, and whether structural repairs are involved. Permit requirements exist partly because Los Angeles has specific Title 24 energy code provisions that affect roofing assemblies, particularly around solar reflectivity for flat roofs. It is worth confirming with your contractor and the local building department before work begins to make sure the project is properly permitted and inspected.

How long does a torch-down roof replacement typically take to complete?

The duration depends on the size of the roof, the condition of the substrate, and the complexity of penetrations and detailing required. Based on the photos from this job, work began on October 2, 2025, with the main roof field substantially completed by October 4, 2025, and follow-up detailing work at skylight curbs documented in January 2026. Larger or more complex roofs naturally take longer, and substrate issues discovered during tear-off — like the extensive rust visible here — can add time if repairs are needed before the new membrane can go down.

Why does Los Angeles's climate cause flat roofs to fail faster than sloped roofs?

Flat and low-slope roofs collect water during rain events rather than shedding it quickly, which means any small gap or weak seam gets tested every time it rains. In Los Angeles, the combination of months of intense UV exposure followed by concentrated rainfall is particularly hard on membrane roofing — UV breaks down the bitumen binder over time, making the membrane brittle and prone to cracking. Thermal cycling from hot days to cooler nights also causes repeated expansion and contraction that stresses seams and flashings. The result is that flat roofs in Southern California tend to require closer attention and more frequent inspection than pitched roofs in cooler or cloudier climates.

What should I look for on my flat roof between professional inspections?

From ground level or a safe vantage point, look for visible bubbling or blistering on the membrane surface, standing water that persists more than 48 hours after rain, and any lifting or separation at the roof edges or around HVAC curbs and skylights. Inside the building, new water stains on ceilings or walls after rain are a reliable indicator that the membrane has been breached somewhere. Parapet walls and the base of any roof-mounted equipment are common weak points worth checking, as the photos from this project show significant deterioration at exactly those locations on the old roof.

Get a Roof Inspection in Los Angeles

If your flat or low-slope roof is showing signs of membrane failure, rust, or recurring leaks, Roof Replacement Inc serves Los Angeles and the surrounding area and can assess what your roof actually needs. Reach out to schedule an on-site inspection and get an honest evaluation of your roof’s condition.

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Project Details

DATE

May 20, 2026

What Our Clients Say

Roof Replacement Inc. provided outstanding service for our roofing repair. The roofing contractors were quick to respond and conducted a thorough inspection before starting the repairs. The roof repair was completed promptly, and the quality of the work was excellent. The team was professional and respectful, ensuring that the area was clean after the job was done. We are extremely satisfied with their service and will definitely use them again if needed. Highly recommend.

Ryland Bear

Researched for 2 years and chose because they had a Better Business Bureau A+ . That and they didn’t time pressure me at all, in fact , Adolpho graciously came back out when I asked if just coating it all over with Silicone would work . He explained everything without rushing or ever making me feel like I was taking up his time. As a single woman homeowner I appreciated that. He is a man of integrity and has gone above and beyond before during and now after the work has been done. I believe him when he says he’ll be there if there’s any other concerns . Highly recommend Adoloho and his team.

Corine Bohrer

We hired Roof Replacement for a complete roof replacement on our home,,, and they exceeded expectations. The local roofing companies we contacted couldn’t match their level of expertise and professionalism. The roofing services included a comprehensive assessment and a detailed plan for the replacement. The new roof is of high quality, and the roof replacement cost was very reasonable. The team was efficient and finished the project ahead of schedule. We highly recommend their services.

Brady Benedict

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Torch Down Roof Replacement in Los Angeles, CA

Torch Down Roof Replacement in Los Angeles, CA