Commercial
Specialized and Flat Roofing in the South Bay
Flat, low-slope, terrace, and deck roofing systems for South Bay commercial buildings and modern homes — installed on occupied properties.
Why roofs
Flat Does Not Mean Level
A low-slope roof only works if water leaves it. Most of the flat-roof failures we are called to inspect across Torrance, El Segundo, and San Pedro are not membrane defects — they are ponding caused by inadequate slope, blocked or undersized drains, or a deck that has deflected over time. Replacing the membrane without fixing the drainage buys a few years and repeats the failure.
We survey slope and drainage first, then specify the system. Single-ply TPO and PVC suit large commercial fields and reflect heat, which matters for cooling load under California's Title 24 requirements. Modified bitumen holds up better under regular foot traffic on service roofs. Liquid-applied and hot-fluid systems are what we use on occupied terraces, planted decks, and podium slabs, where a leak lands in somebody's living space rather than a plenum.
Roofing an Occupied Building
Almost none of this work happens on an empty building. Tear-off is noisy, hot-applied systems carry odor, and both need to be sequenced around tenants, business hours, and the parking that the crane or hoist will occupy. We phase by section so the building stays weathertight overnight, coordinate notice with property management, and keep roof access and life-safety routes clear throughout.
What the Work Covers
- Slope, drainage, and deck condition survey before any system is specified.
- TPO, PVC, modified bitumen, and liquid-applied membrane systems.
- Terrace, balcony, planted deck, and podium slab waterproofing.
- Drain, scupper, and overflow correction — not just membrane replacement.
- Flashing, parapet, curb, and penetration detailing.
- Phased installation on occupied buildings, weathertight at the end of each day.
Why DECOMA
One license, three disciplines, forty years.
Family-run South Bay general contractor since 1978. We design, build, and manage — under one license — so the team you start with is the team that hands you keys and the team that answers the phone when something needs fixing in year ten.
- Years building
- 48+
- Projects delivered
- 3,000+
- Repeat clients
- 300+
- CSLB Class
- A/B
Service areas
Roofs across the South Bay.
Born in Harbor City, working across LA County since 1978. Same crew, same license number, same shop at 25941 Frampton Ave, Harbor City.
Talk to a contractor
Tell us about your project.
One business day for a scope, timeline, and budget range. CSLB #375508 A/B.