Metal roofing
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Flat & low-slopeFree roof inspection with deck photos before we talk money - GAF and Owens Corning certified installation
Fast, Reliable Roof Installation Across Commerce
Roof installation in Commerce, CA typically runs $8,500 – $26,000 depending on whether you’re roofing a mid-century warehouse, a commercial storefront, or one of the city’s few single-family homes. Most Commerce projects are flat or low-slope commercial roofs, and we complete them in 5 – 12 working days once materials arrive. Our crews know Commerce’s industrial districts block by block: the aging built-up roofs along Eastern Avenue, the modified bitumen systems near the Citadel Outlets, the single-ply membranes on Telegraph Road warehouses. Call (213) 521-8272 for a written line-item quote, or keep reading to understand what actually drives roofing costs in this city.
Why Mercer Roofing Co Los Angeles Is Commerce’s Preferred Roof Installation Company
Commerce isn’t a typical roofing market. Most of the city is warehouse, distribution, and light industrial, which means the roofer you hire has to understand flat roof chemistry, drainage slopes, and seam welding, not just shingle nailing. Our crews have torn off and replaced dozens of Commerce roofs, and we know what fails here: gravel-surfaced built-up roofs from the 1960s through 80s, modified bitumen that’s alligatored beyond patching, and TPO seams that split under constant truck vibration.
Every technician who arrives at your Commerce property is background-checked, identity-verified, and in a clean, marked uniform with a photo ID badge at the door. Before they arrive, you get their name and photo sent to you. That’s the Threshold Standard, and it’s not optional for any Mercer job. Grant Whitlock leads our team and holds every project to the same written-price rule: no work starts until you have the number on paper.
We answer the phone live, 24/7. When a Commerce warehouse owner calls about a leaking skylight curb at 6 a.m. before a shift starts, a real person picks up. Not a voicemail. Not a call-back form.
Styles & brands we work with
Roof Ventilation in Commerce
Roof ventilation in Commerce is a different job than it is in residential Los Angeles. Commerce’s inland position means intense summer UV cooks roof surfaces, and without proper ventilation, that heat transfers straight into the building. For the few single-family homes here and the office portions of commercial structures, we install intake and exhaust ventilation that keeps attic or plenum temperatures within 15 – 20 degrees of outside air. A typical roof ventilation installation in Commerce runs $900 – $2,400 depending on roof area and whether we’re adding ridge vents, box vents, or powered exhaust.
Why Ventilation Matters More Inland
Commerce sits inland from the coast, so it doesn’t get the marine layer that keeps places like Long Beach cooler. Summer roof surface temperatures here regularly exceed 150°F. Without moving air, that heat bakes the underside of your roofing membrane and shortens its life by years.
What We Check Before Adding Vents
We measure your existing intake area first. A common Commerce mistake is adding exhaust vents without enough soffit or intake vents to balance the system. We calculate net free vent area before quoting, so you’re not paying for vents that can’t do their job.
Roof Flashing Installation in Commerce
Roof flashing installation in Commerce is where cheap roofing goes to die. Flashing is the metal that seals the places where your roof meets a wall, curb, penetration, or edge, and on Commerce’s flat roofs those transitions are everywhere: skylight curbs, HVAC penetrations, parapet walls, drain sumps. A full flashing replacement on a typical Commerce commercial roof runs $2,500 – $7,800, depending on linear footage and how many penetrations need attention. We install it with stainless steel fasteners and hot-dip galvanized edge metal, because in Commerce’s combination of sun, occasional salt air, and vibration, zinc-plated hardware corrodes early and opens the exact seams that leak.
Flashing Failure at Penetrations
Most Commerce roof leaks aren’t in the field of the roof. They’re at the flashing. When a roof has a dozen skylight curbs or a row of exhaust fan penetrations, each one is a potential entry point for water. We strip the old flashing, inspect the curb or penetration, and re-flash with metal that’s actually rated for the conditions here.
Parapet and Drip Edge Work
Parapet walls are standard on Commerce commercial buildings, and they fail at the cap. Water gets behind the cap flashing, runs down the wall, and rots the substrate. We replace parapet caps with hot-dip galvanized metal and seal every joint with a UV-stable sealant that won’t crack in the first two Commerce summers.
Trusted Brands We Service in Commerce
We install and repair roofs using manufacturer-recognized systems from GAF, Atlas, and Tamko, among others. For Commerce’s flat and low-slope buildings, we regularly specify GAF TPO and Atlas modified bitumen systems, because they hold up to the specific conditions here: prolonged UV, heavy rain events, and constant vibration from truck traffic. If you already have a roof under manufacturer warranty, we’ll work within the brand’s spec so you don’t void it. We order Commerce stock directly through local supply yards, which means materials arrive faster than if we had to route them from across the county.
See the difference
Before
After
Before
After
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AfterCommon Roof Installation Problems We See in Commerce Homes
Here’s what actually goes wrong on Commerce roofs, and what we do differently:
- Alligatoring on original built-up roofs. Decades of UV exposure crack the asphalt surface into a pattern that looks like alligator skin. Once alligatoring is widespread, patching is a band-aid. The fix is a full tear-off and new membrane.
- Corroded fasteners at flashing and drip edge. Occasional salt air near Commerce eats zinc-plated hardware faster than people expect. We specify stainless steel and hot-dip galvanized metal on every flashing detail.
- Seam splits on modified bitumen. Constant forklift and truck vibration, especially on loading docks and near Eastern Avenue’s warehouse rows, opens seams on older modified bitumen roofs that have no movement joints. A new roof here needs movement-tolerant details.
- Gravel loss on original built-up roofs. During heavy rain, gravel washes toward drains and scuppers, leaving bare asphalt exposed. The next heat wave cracks it. If your Commerce roof still has gravel surfacing, it’s on borrowed time.
Pricing for Roof Installation in Commerce, CA
A full tear-off and new TPO membrane on a typical 5,000 sq ft Commerce warehouse runs $18,000 – $32,000. A smaller commercial storefront, say 1,500 – 2,500 sq ft, runs $9,500 – $16,000 for a single-ply or modified bitumen system. The few single-family homes in Commerce with pitched shingle roofs run $8,500 – $14,000 for a standard architectural shingle replacement. What moves the price: roof size, number of penetrations, decking condition, whether the old roof has to be fully torn off, and the hardware spec. We’ll give you a written line item quote before any work starts. Call (213) 521-8272 for a free estimate.
We Also Serve Cities Near Commerce
Our crews cover Commerce and the surrounding communities, including Roof Installation for commercial and residential properties across the area. We also serve Los Angeles, Burbank, South Gate, and Lynwood. Learn more about our work in Commerce or call us to schedule a roof assessment.
Serving Commerce, CA - Our Local Coverage Area
We’re based in the Commerce area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Roof Installation in Commerce
Commerce roofs are mostly flat or low-slope commercial systems that rely on welded seams, membranes, and flashing details to shed water, while residential roofs use shingles and gravity slopes. Flat roofs here also carry UV, vibration, and occasional salt-air stress that pitched shingle roofs don’t face at nearly the same intensity. Call (213) 521-8272 for a free assessment of your specific roof.
Salt air accelerates corrosion on standard zinc-plated hardware, especially at parapet flashing, drip edges, and roof penetrations. We specify stainless steel fasteners and hot-dip galvanized edge metal on every Commerce roof so your flashing doesn’t rust open before the membrane wears out.
Alligatoring is the cracked, scale-like pattern that forms on old built-up roof asphalt after years of UV exposure and heat cycling. Commerce’s inland sun is intense, so an original 1970s built-up roof that’s lived its life here often shows alligatoring across most of its surface. Once it’s widespread, the roof needs replacement, not patchwork.
No. Architectural shingles are for sloped roofs. A flat or very low-slope Commerce warehouse needs a membrane system: TPO, EPDM, modified bitumen, or PVC. Installing shingles on a flat roof guarantees ponding water and leaks. Call (213) 521-8272 and we’ll spec the right membrane for your building’s slope and use.
Expect to add 8 – 15% over a standard inland spec for stainless fasteners, hot-dip galvanized edge metal, and UV-stable sealants. On a $22,000 commercial roof, that’s roughly $1,800 – $3,300 more upfront. But the inland-spec version often needs flashing and fastener replacement within 7 – 10 years, while the coastal-spec version is still going at 20. Call (213) 521-8272 for a line-item quote.
Written by Grant Whitlock, Owner at Mercer Roofing Co Los Angeles, serving Commerce since 2000.