--- title: "Commercial Roofing Los Angeles: Low-Slope Repair, Coating and Reroofing" description: "Commercial roofing in Los Angeles: TPO, PVC, modified bitumen and built-up roofs, repairs, silicone coatings and reroofs that account for Title 24 rules." url: "https://power-roofing.com/services/commercial-roofing/" updated: "2026-11-03" --- Commercial Roofing # Commercial Roofing Los Angeles: Low-Slope Repair, Coating and Reroofing [Call (424) 380-5776](tel:+14243805776) [Request Free Estimate](https://power-roofing.com/contact-us/) Power Roofing provides commercial roofing in Los Angeles for offices, retail buildings, apartment complexes and warehouses: repairs, coatings and full replacement of flat and low-slope roofs, working with TPO, PVC, modified bitumen and built-up (hot mop) systems. We hold the C-39 roofing and General B licenses (#1073368), and our offices in Los Angeles, Sherman Oaks and Irvine cover commercial properties throughout Los Angeles, Orange and Ventura counties. A commercial roof raises different questions than a house: who is affected while the work happens, whether the roof can be restored instead of replaced, and which California energy rules a reroof sets off. This page walks through each one and then explains what drives the cost. To set up a roof assessment, call us or [request a free inspection](https://power-roofing.com/contact-us/). Flat roof replacement, Costa Mesa by Power Roofing Flat roofs Flat roof replacement Costa Mesa View project → Flat roof replacement, Huntington Beach by Power Roofing Flat roofs Flat roof replacement Huntington Beach View project → Flat roof installation, Santa Ana by Power Roofing Flat roofs Flat roof installation Santa Ana View project → Flat roof installation, Los Angeles by Power Roofing Flat roofs Flat roof installation Los Angeles View project → Flat roof installation, Bel Air by Power Roofing Flat roofs Flat roof installation Bel Air View project → Flat roof installation, Lomita by Power Roofing Flat roofs Flat roof installation Lomita View project → ## Low-slope roof systems for commercial buildings Commercial buildings typically have flat or low-slope roofs. Water stays on them longer than on a pitched roof, so they depend on a continuous membrane, sealed seams and drains that work. These are the systems we work with: | System | How it is built | Where it fits | | --- | --- | --- | | TPO | Single-ply sheets with heat-welded seams, usually white | Large, open roofs where a reflective surface helps meet the cool-roof rules | | PVC | Single-ply sheets with heat-welded seams | Roofs exposed to grease or chemicals, such as above restaurant kitchen exhausts | | Modified bitumen | Asphalt-based rolls laid in plies, torch-applied, cold-applied or self-adhered, often with a reflective cap sheet | Roofs with regular foot traffic and many penetrations | | Built-up (hot mop) | Alternating plies of felt and hot asphalt, finished with gravel, a cap sheet or a coating | Smaller commercial and apartment roofs, and repairs to existing built-up roofs | | Silicone coating | A liquid-applied membrane over a sound existing roof | Restoring an aged but dry roof without a tear-off | Older buildings often carry EPDM (rubber) roofs as well, and we repair those too. Flat and low-slope roofs on houses and new construction are covered on our page about [new roof installation in Los Angeles](https://power-roofing.com/services/new-roof-installation/). ## Repair, restore, recover or replace? A commercial roof that leaks is not always a roof that needs replacing. The choice depends on what is under the surface: 1. **Repair** when the membrane is sound and the leaks come from specific details: an open seam, a failed flashing at a curb or parapet, a clogged drain. 2. **Restore with a coating** when the membrane is weathered but still attached, and the insulation and deck below it are dry. A silicone coating adds a new waterproof, reflective surface over the existing roof without demolition. 3. **Recover**, meaning a new roof covering laid over the existing one, when the old roof is a sound base. California’s building code limits this: no recover over a roof that is water-soaked or deteriorated, over slate, clay or cement tile, or over a roof that already has two or more applications of roofing. 4. **Replace** when the insulation is wet, the deck is damaged or the layer limit is reached. The roof comes off down to the deck and a new system goes on; our page on [roof replacement in Los Angeles](https://power-roofing.com/services/roof-replacement-los-angeles/) walks through that process. Wet insulation is the deciding detail. A coating or recover laid over a wet roof traps the water in the building, so soft spots, blisters and other signs of trapped moisture are checked before any option is priced. Our coating projects include a 6,800 sq. ft. flat roof finished with silicone coating in Los Angeles and a roof restoration in San Marino done with no demolition. Flat roof replacement, Los Angeles by Power Roofing Flat roof replacement, Los Angeles, 2023 Flat roof replacement, Costa Mesa by Power Roofing Flat roof replacement, Costa Mesa, 2022 Flat roof replacement, Long Beach by Power Roofing Flat roof replacement, Long Beach, 2022 ## California energy rules when you reroof a commercial building California’s Energy Code (Title 24, Part 6) applies to reroofing, not only to new buildings, and permit applications filed on or after January 1, 2026 fall under the 2025 edition. The California Energy Commission’s [2025 Nonresidential Compliance Manual](https://www.energy.ca.gov/publications/2025/2025-nonresidential-compliance-manual-2025-building-energy-efficiency-standards) sets out when a reroof has to meet cool-roof and insulation requirements: - **The trigger.** The rules apply when 50 percent or more of the roof area, or more than 2,000 square feet of it, is replaced, recovered or recoated, whichever is less. A small repair does not trigger them. - **Cool roof.** For nonresidential low-slope roofs, the prescriptive requirement in all 16 climate zones is an aged solar reflectance of at least 0.63 and a thermal emittance of at least 0.75, or a Solar Reflectance Index of at least 75. A lower reflectance is allowed when additional insulation is installed. - **Rated products.** Roofing used to meet the requirement is certified and labeled by the Cool Roof Rating Council. - **Insulation.** When a low-slope roof is replaced or recovered, the altered area is insulated to the code’s Table 141.0-C: for nonresidential buildings, R-17 or R-23 continuous insulation depending on climate zone, or an equivalent U-factor. Two exceptions apply: a recover that adds new R-10 insulation above the deck does not have to reach the Table 141.0-C level, and recoating a roof that already has a coating, as maintenance, is exempt from this step. The manual’s own example also notes that overlaying the existing roof surface, instead of replacing it, does not trigger the insulation requirement. - **Conditioned space only.** On a warehouse, the requirements cover the roof over conditioned areas such as offices (where those walls reach the roof), not the roof over unconditioned storage. Rooftop equipment changes the insulation math. When HVAC units stay in place instead of being disconnected and lifted, the added insulation can be limited to the greater of R-10 or the thickness that keeps the manufacturer’s required height between the membrane and the top of the unit’s base flashing. Hotels and motels have their own values, and apartment buildings may fall under the code’s multifamily or residential provisions instead of these nonresidential ones; we confirm which rules apply to your building. These details are settled before the estimate, because they change both the price and the schedule. Flat roof installation, Bel Air by Power Roofing Flat roof installation, Bel Air, 2023 Flat roof repair, San Marino by Power Roofing Flat roof repair, San Marino, 2023 Flat roof replacement, Montebello by Power Roofing Flat roof replacement, Montebello, 2021 ## Planning a reroof on an occupied building A commercial reroof happens over people who are working, shopping or living in the building. Before work starts, settle these points with your roofer: - **Access and notice.** When crews and materials arrive, which areas close, and where staging and the dumpster go. - **Rooftop equipment.** Which HVAC units, exhaust fans or solar arrays need disconnecting or lifting, and who does that work. - **Odor and noise.** Hot-mop asphalt has a strong smell, so air intakes and occupied rooms count when choosing between hot, torch-applied, cold-applied and heat-welded systems. - **Open roof overnight.** How much roof will be open at a time and how it is protected if rain comes. - **Records.** Photos before, during and after the work, for owners, managers and insurers. We coordinate with the building’s other contractors on these jobs and follow OSHA guidelines on the job. One property owner whose rental roof was damaged in a storm wrote that our team “coordinated access with our tenant, documented the damage, and sent us completion photos.” ## Commercial roof repair: where low-slope roofs leak Commercial roof leaks tend to start at the same few details, and a lasting repair depends on finding the right one: - ponding water that is still there days after rain and ages the membrane faster; - clogged drains and scuppers, often from leaves and debris blown onto the roof; - open seams on single-ply roofs, or blisters and splits on built-up and modified bitumen roofs; - flashing at parapet walls, HVAC curbs, pipes and roof hatches; - punctures and wear from service technicians walking to rooftop units. Commercial leaks are part of our [roof repair in Los Angeles](https://power-roofing.com/services/roof-repair-los-angeles/) service. On a building with an aging roof, assessing the whole roof shows whether repairs will keep up or a coating, recover or replacement is due. We also set up maintenance programs for commercial buildings through our [roof maintenance in Los Angeles](https://power-roofing.com/services/roofing-maintenance/) service; documented maintenance keeps warranty coverage valid. Flat roof installation, Santa Ana by Power Roofing Flat roof installation, Santa Ana, 2024 Flat roof replacement, Huntington Beach by Power Roofing Flat roof replacement, Huntington Beach, 2025 Flat roof installation, Lomita by Power Roofing Flat roof installation, Lomita, 2023 ## What drives the cost of a commercial roof We price commercial roofs after seeing them, because the same square footage can mean very different work. The main factors: - roof area and shape, including parapets, levels and the number of penetrations; - the system chosen and the manufacturer warranty that comes with it; - tear-off: how many existing layers come off, and disposal; - the condition of the deck and insulation, especially wet insulation that must be replaced; - Energy Code insulation and cool-roof requirements set off by the size of the job; - rooftop equipment that must be disconnected, lifted or re-flashed; - drainage corrections such as tapered insulation, crickets or added drains; - access, building height, staging and any phased or after-hours work. ## Commercial roofing questions ### How long does a commercial reroof take? Commercial installations typically take 5-10 days or longer depending on system type and building size. Rooftop equipment, phased work around tenants and any deck or insulation found wet once the old roof is open all count toward that schedule, which is why they are settled before work starts. ### Can an old commercial roof be restored instead of replaced? Often, yes, if the membrane is still attached and the insulation and deck are dry. A silicone coating can restore it without a tear-off. If the roof is wet or deteriorated, replacement is the honest answer. ### What happens when a commercial roof leaks after hours? Roof emergencies don’t follow business hours, and we offer 24/7 emergency response. We dispatch a team to stabilize the situation, prevent further damage, and implement temporary solutions. After stabilization, we assess full damage extent, provide detailed estimates, and schedule permanent repairs at times convenient for you. ### Does a commercial reroof need a permit? Reroofing needs a building permit from the city or county where the building stands, and Energy Code compliance for the reroof is documented through that permit. City of Los Angeles reroof permit descriptions themselves note that a cool roof may be required for non-residential buildings under Title 24, Part 6, Section 141.0(b)2B, and the city’s permit records for our license include built-up reroofs. Flat roof replacement, Norwalk by Power Roofing Flat roof replacement, Norwalk, 2021 Flat roof installation, Garden Grove by Power Roofing Flat roof installation, Garden Grove, 2022 Flat roof installation, Los Angeles by Power Roofing Flat roof installation, Los Angeles, 2024 [Google](https://maps.google.com/maps?cid=9761061374546370943) > "I wanted to take a moment to express my utmost gratitude to Chris and the entire team at Power Roofing for their exceptional service and expertise in installing our commercial flat roof in Santa Monica." Read the full review → E **Erika C.** [Google](https://maps.google.com/maps?cid=9761061374546370943) > "I am more than happy to recommend Power Roofing to anyone seeking commercial roofing services in Hollywood or the surrounding areas." Read the full review → T **Tyrell D.** [Google](https://maps.google.com/maps?cid=4808282510465198429) > "They has done an excellent job re-roofing several of our historic buildings. I would highly recommend him" Read the full review → J **Johan M.** [Thumbtack](https://www.thumbtack.com/ca/los-angeles/roofing/power-roofing/service/415072168072896514) > "Power Roofing team completed new roof on two-story 17-unit apartment building. They were very efficient and affordable. It was done ahead of schedule and it looks great." Read the full review → R **Robert R.**Roof Installation or Replacement [Google](https://maps.google.com/maps?cid=9761061374546370943) > "A recent storm damaged the roof on our rental property. The team coordinated access with our tenant, documented the damage, and sent us completion photos." Read the full review → K **Kaylee K.** [Yelp](https://www.yelp.com/biz/power-roofing-los-angeles) > "Very impressed with Israel and his crew. After a bad roof installation by a different company resulted in major damages to our house, we knew we had to get the right company to replace our faulty flat roof." Read the full review → J **James L.** ## Get a commercial roof assessment Send us the building address, the roof’s age if you know it and what is happening: leaks, ponding, an upcoming sale or refinance, or a reroof you need to plan. We will inspect the roof, check drains, seams, flashings and signs of trapped moisture, and lay out repair, coating and replacement options with the code requirements that apply. Call us or [request a free inspection](https://power-roofing.com/contact-us/), or browse [all our roofing services](https://power-roofing.com/services/). [Call (424) 380-5776](tel:+14243805776) [Request Free Estimate](https://power-roofing.com/contact-us/)