Completed flat roof installation with San Gabriel Mountains GAX Roofing
Flat Roofs

Flat Roof Installation
in Rancho Cucamonga

TPO, PVC, EPDM, and modified bitumen for residential and commercial flat roofs. Built for California heat with proper drainage and waterproofing.

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C39 Licensed & Insured
TPO · PVC · EPDM · Mod Bit
Residential & Commercial
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What We Do

Flat Roofs That
Actually Hold Up

Flat roofs require a different level of attention than pitched roofs. Standing water, thermal expansion, and UV exposure are all bigger factors — and a flat roof installed without proper drainage planning or quality materials will fail faster and cause more damage than almost any other roofing failure.

We've installed flat roofs across the Inland Empire since 2023 and we know what works in this climate. We'll recommend the right membrane system for your property, budget, and usage — and install it to last.

Systems We Install

  • TPO (Thermoplastic Polyolefin) — most popular for residential, energy-efficient white membrane, excellent for IE heat
  • PVC — highly durable, chemical resistant, great for roofs with HVAC or kitchen exhaust exposure
  • EPDM (Rubber) — cost-effective, long-lasting, excellent UV resistance
  • Modified Bitumen — reliable workhorse system, excellent for complex roofs with many penetrations
  • Reflective coatings over existing systems when applicable

What We Assess Before Every Install

  • Drainage — existing drains, slope, and ponding areas
  • Deck condition — wood rot, moisture damage, structural integrity
  • Penetrations — HVAC units, vents, pipes, solar mounts
  • Parapet walls and edge conditions
  • Existing system condition if doing a recover vs. tear-off
Completed flat roof with mountains in background Flat roof with solar panels adjacent

Frequently Asked Questions

How long does a flat roof last in Southern California?

Quality TPO or PVC systems carry 15–25 year manufacturer warranties. Modified bitumen typically runs 15–20 years. Lifespan depends heavily on installation quality, drainage design, and maintenance.

Which flat roof system is best for the Inland Empire?

TPO is our most common recommendation for residential flat roofs in the IE. Its white reflective surface handles the heat well, it's cost-effective, and it performs reliably when properly installed and seamed.

My flat roof is ponding water — is that a problem?

Standing water (ponding) that remains more than 48 hours after rain accelerates membrane degradation and is a sign of a drainage problem. It's worth having us take a look — it may be addressable without a full replacement.

Can I put solar on a flat roof?

Yes. We coordinate with solar installers regularly to ensure penetrations are properly flashed and waterproofed. If you're planning solar, let us know — we'll design the install with that in mind.

Flat roof issues?
Free estimate — no obligation.

(909) 910-2720