# Flat roofing, system by system: TPO, PVC, EPDM, modified bitumen, spray foam.

Mammoth Roofing & Exteriors · https://mammothroofs.com/services/commercial-roofing/flat-roofing/ · (210) 934-9074

Six flat-roof systems, one honest comparison. Each has a building it's right for and a failure it's prone to. We inspect, find the moisture, and recommend the system on the numbers, with a scope you can put in front of an owner or a board.

## What each one is, and where it belongs.

- **TPO**: Single-ply thermoplastic, heat-welded seams, highly reflective. The most common new commercial roof in Texas: energy-efficient and cost-effective. Typically 20–30 years.

- **PVC**: Single-ply with the best chemical and grease resistance: restaurants, kitchens, plants. Reflective and durable; costs more than TPO.

- **EPDM**: Synthetic rubber, flexible, decades of track record, easy to repair. Dark by default, so less reflective unless coated.

- **Modified bitumen**: Multi-layer asphalt sheets, torch or cold applied. Tough under foot traffic, cost-effective, good for smaller flat roofs and repairs.

- **Spray polyurethane foam**: Seamless insulation and roof in one, coated for UV. Excellent insulation; needs a good installer and regular recoating.

- **[Coatings](https://mammothroofs.com/services/commercial-roofing/roof-coatings/)** (Restoration): Not a system on their own, but the way to add 10–20 years to any of the above once it's sound.

## When to use which.

Typical figures; the building, the insulation and the drainage change all of them. The inspection report gives the numbers for your roof.

| System | Typical life | Strength | Watch for | Relative cost |
| --- | --- | --- | --- | --- |
| TPO | 20–30 years | Reflective, energy-efficient, welded seams | Quality varies by product; seams need a skilled crew | $$ |
| PVC | 20–30 years | Chemical and grease resistance, reflective | Higher material cost | $$$ |
| EPDM | 20–30 years | Flexible, repairable, proven | Dark unless coated; seams are taped, not welded | $$ |
| Modified bitumen | 15–25 years | Foot traffic, small roofs, repairs | Heavier, less reflective | $$ |
| Spray foam | 20+ years with recoating | Insulation value, seamless | Installer-dependent; recoat every 10–15 years | $$$ |

_Sample ranges shown for design. The written inspection determines the scope and price._

## What the inspection decides.

- **Moisture survey**: Wet insulation is the deciding fact. We find it before anyone recommends a coating over it.

- **Seams, flashings, drains**: Most flat-roof leaks are at the details, not in the field. Repairs here are cheap and fast.

- **Coat or replace**: A sound membrane gets a coating and 10–20 more years. A wet or failed one gets replaced, because coating it is money down a drain.

- **Warranty**: The manufacturer's lifetime material warranty on new installs, the life of that system on its written terms, and Mammoth's 10-year workmanship warranty on everything. Terms in writing.

## Straight answers before you book.

### What are the most popular flat-roof materials?

TPO, PVC, EPDM and modified bitumen. TPO and PVC lead on energy efficiency; EPDM on flexibility and repairability; modified bitumen on cost for small roofs.

### Which is most energy-efficient?

Reflective TPO and PVC, which cut cooling loads noticeably in Texas summers. A reflective coating gets an older roof most of the way there.

### How do I choose?

Building size, roof slope, what's underneath, chemical exposure, budget and how long you'll own it. The report recommends one and says why.

### Is the inspection really free?

Yes — it's the same Roof Grade visit for every service. Attic first, 75–150 photos, the 32-point Hunter-Gatherer Report, a letter grade and a plain-English verdict. You get the written report whether you hire us or not.

### Will you tell me if I don't need the work?

Yes. An A grade is a handshake and a date to look again. A B means a few small repairs, priced in the open, on a roof with years left in it. We'd rather be the roofer you call in ten years than the one who sold you a roof you didn't need.

### What warranty comes with the work?

Repairs carry a workmanship warranty in writing on the invoice. Full replacements carry the Mammoth Two Tusk Limited Lifetime Warranty: our 10-year workmanship warranty on the installation, plus the manufacturer's lifetime material warranty on the materials, which means the life of that product on the manufacturer's written terms. Ask us for the warranty document and read it before you sign.