Commercial Roofing Types: TPO, EPDM, Metal and More Compared

Published: November 6, 2026 · Crawford Residential and Industrial Repair, roofing West Tennessee since 2012

National figures from This Old House’s flat roof replacement guide (updated March 16, 2026, builder-grade materials). Not Crawford prices.

Most commercial roofing types fall into five families: single-ply membranes (TPO, EPDM and PVC), modified bitumen, built-up roofs, metal panels, and liquid coatings or spray foam laid over an existing roof. On a flat or low-slope building, the choice comes down to how the roof drains, what sits and walks on it, what the building is used for and how long you plan to own it. This guide compares each type, with national cost and lifespan figures, and explains what tends to fail on each one on West Tennessee buildings.

If you already have a leak or a roof that needs looking at, our commercial roofing page explains how we inspect and repair business roofs across Madison, Gibson and Dyer Counties.

Metal panels over a commercial patio. Pitched metal like this sheds water fast; the flat roof behind most storefronts does not.

Low-Slope vs Steep-Slope Commercial Roofs

Commercial roofs split first by slope. A steep-slope roof, like most houses and some churches, offices and restaurants, sheds water quickly and can use shingles, tile or metal panels. A low-slope roof looks flat from the ground but is built with a slight pitch toward drains, scuppers or gutters. Water moves slowly across it, so the covering has to be a continuous, sealed surface rather than overlapping pieces.

Most strip centers, warehouses, shops and industrial buildings in Jackson and the surrounding towns sit under low-slope roofs. That is why the rest of this guide spends most of its time on membranes and asphalt-based systems.

Single-Ply Membranes: TPO, EPDM and PVC

Single-ply roofs are large sheets of synthetic membrane laid over insulation and fastened, glued or held down with ballast. This Old House’s 2026 flat roof guide puts EPDM at $9 to $13 per square foot and TPO at $8 to $11. Its separate TPO guide gives a wider $4 to $10 range, based on HomeGuide and Angi data, which shows how much insulation, tear-off and access move the number.

TPO (thermoplastic polyolefin)

TPO is the white membrane you see on many strip malls and warehouses. Its seams are heat-welded with hot air, which makes a strong joint when it is done right. This Old House says it reflects UV light, resists oil and grease, and lasts 15 to 30 years with proper care. The weak points are seams that were not welded well and flashings at walls, curbs and rooftop units.

EPDM (rubber)

EPDM is a black or white synthetic rubber. It flexes through temperature swings without cracking, and This Old House’s TPO guide puts its life at about 30 years. Its seams are taped or glued rather than welded, so seam adhesion is the usual failure point as a roof ages. The same guide notes EPDM does not hold up well to oil and grease, which matters on restaurant roofs near kitchen exhaust.

PVC

PVC is another heat-welded thermoplastic membrane, similar in look to TPO. It is often chosen for roofs that see grease or chemicals, and it generally costs more than TPO or EPDM.

Modified Bitumen

Modified bitumen is an asphalt-based roof built from rolls that are torched, mopped or self-adhered in layers. This Old House prices it at $7 to $9 per square foot and gives it a 10 to 20 year life. The layered build resists cracking through freeze-thaw cycles, which West Tennessee winters bring. It tends to wear at the laps between rolls and around penetrations.

Built-Up Roofs (Tar and Gravel)

A built-up roof is the classic “tar and gravel” roof: several plies of felt and hot asphalt finished with gravel or a mineral cap. This Old House prices it at $7 to $9 per square foot with a 10 to 20 year life, and notes that the multiple layers help seal small punctures, which suits roofs with foot traffic or falling branches. Built-up roofs are heavy, and they are harder to inspect because the gravel hides the surface.

A covered patio under a dark metal roof. Metal’s weak points are fasteners, seams and the sealant around them.

Metal Roof Panels

Metal panels cover everything from shops and warehouses to restaurant canopies, on both pitched and low-slope buildings. This Old House prices metal at $15 to $21 per square foot, the most expensive option in its flat roof table, with a 40 to 100 year life and resistance to high winds and large hail. On a metal roof, the trouble spots are backed-out fasteners, failed seams and sealant, and the movement of the panels as they heat up and cool down through a Tennessee summer.

Coatings and Spray Foam

Acrylic and silicone coatings are rolled or sprayed over an existing roof that is still sound, and spray polyurethane foam is sprayed on as both insulation and roof surface. This Old House says coatings should be reapplied about every five years. They can extend the life of a roof in decent shape, but they do not fix wet insulation or a deck that has already failed, so the roof needs a proper inspection first.

Commercial Roofing Types Compared

Costs and lifespans: This Old House flat roof guide (March 16, 2026) and This Old House TPO guide (June 5, 2026). Failure points are what we see on the roof.

Which Commercial Roof Type Is Best for Your Building?

There is no single best commercial roof. A few questions narrow it quickly:

• How does it drain? Water that sits on a low-slope roof finds every weak seam. A roof with ponding needs the drainage fixed whatever covering goes on.
• What is on the roof? HVAC units, vents and skylights each need flashing. Roofs with heavy foot traffic for equipment service benefit from a tougher surface or walk pads.
• What does the building do? A restaurant with kitchen exhaust needs a membrane that resists grease. A warehouse with nothing on the roof has more options.
• How long will you own it? A long hold can justify metal or a heavier membrane. A shorter one may favor repairing and maintaining what is there.

Often the right answer is not a new roof at all. A roof with a few failed details can usually be repaired and kept on a maintenance schedule for years.

What a Commercial Roofer Does on an Existing Roof

Our commercial work is about keeping the roof you have watertight. Every job starts on the roof, not with a quote over the phone: we walk the whole surface, check the seams and the flashing at every wall and penetration, look for ponding and wet spots, and match what we see on top with where water shows up inside. We photograph everything and give you a written estimate before any work starts. Then we tell you straight whether the roof needs a repair, more maintenance, or a plan for replacement down the road.

We repair flat and low-slope membranes, modified bitumen and metal panel roofs, rebuild failed flashing, and set up maintenance visits in spring and fall. We work on business roofs from our base in Jackson out to Humboldt, Milan, Medina, Trenton and Dyersburg. To get a roof looked at, see our commercial roofing services or request a free inspection below.