If you own a warehouse off 35W, a strip center in north Fort Worth, or a restaurant building anywhere in Tarrant County, the odds are good that the white membrane on your roof is TPO. It has been the default for low-slope commercial work for about two decades now, and most owners have never been told anything about it beyond the fact that it is there.
That is a bad position to be in when somebody calls you about a leak. So here is the owner-level version: what the material is, what it is good at, where it gets you in trouble in Texas, and how to tell a repair conversation from a replacement conversation.
What TPO is, in plain terms
TPO stands for thermoplastic polyolefin. It arrives on a truck in big rolls, it is rolled out across your roof deck over insulation board, and it is fastened or adhered down. It is a single layer of membrane, which is why the industry calls it single-ply, and it is a very different animal from the old built-up tar and gravel systems it replaced.
The rolls are wide, but they are not as wide as your building. So there are seams. Every seam is a place two sheets of membrane overlap, and the seams are where a single-ply roof lives or dies.
Heat-welded seams, and why the word welded matters
This is the part worth understanding, because it is the difference between a roof that lasts and a roof that starts calling you in year three.
TPO seams are made with a hot air welder. The tool pushes air at several hundred degrees between the two overlapping sheets and a roller presses them together behind it. The plastic on both faces melts and fuses. When it cools, those two sheets are one sheet. There is no adhesive in the joint, nothing to dry out, nothing with its own separate lifespan. Pull a properly welded seam apart and the membrane tears through the body of the material before the weld lets go.
A glued seam is not that. Adhesives and seam tapes have a service life of their own, they are sensitive to how clean and dry the surfaces were on install day, and they fail at the bond line while the membrane on either side is still perfectly good. Older single-ply systems and cheap corner-cutting installs both rely on them.
So when somebody quotes you a TPO roof, the question to ask is whether every seam and every detail is hot air welded, including the flashings around curbs and drains and pipes. A crew that welds the field and then caulks the details has given you a roof with a good middle and weak edges, and edges are where water goes.
We probe seams with a blunt tool on every commercial roof we walk. A weld either holds or it does not, and it takes about two seconds per foot to find out.
The white membrane and a Texas summer
TPO is usually white, and that is functional. A dark roof absorbs sun and dumps that heat into the roof assembly and then into your building. A reflective white surface sends a large share of it back at the sky instead. Your rooftop units are pulling air off a surface that is meaningfully cooler on a July afternoon, which means they cycle less to hold the same interior temperature.
We are not going to hand you a percentage on your power bill. Anybody who does is making it up, because the number depends on your insulation, your equipment, your ceiling height, your occupancy, and how the building is run. What we will say is that on a North Texas afternoon the difference between standing on a white membrane and standing on a black one is the kind of thing you feel through your boots, and the assembly under it is living the same difference for four months a year.
The reflectivity does drop as the surface picks up dirt and airborne grime. Washing a TPO roof restores a good part of it, which is one of several reasons the maintenance rhythm further down matters.
Where TPO fits well and where it fights you
TPO earns its place on clean, large, low-slope decks. Warehouses and distribution buildings are close to ideal: big uninterrupted spans, few penetrations, light foot traffic, positive drainage. Retail and office buildings do well too. That is the bulk of what we install on warehouse and industrial properties in this area.
Three situations give it trouble, and you should know if you are in one of them.
- Grease exhaust. Animal and vegetable fats attack TPO. A kitchen exhaust fan puts a fine mist of grease onto the membrane downwind of it, and over time that softens and degrades the material in a spreading stain around the unit. This is the single most common reason we get called to restaurant roofs, and it is why grease containment on the hood curbs plus a sacrificial walkway or protective membrane in the drift zone belongs in the plan from day one rather than after the damage.
- Ponding water. A low-slope roof is supposed to drain, not hold. Water standing more than a couple of days after rain means the deck sags, the drains are undersized or blocked, or the insulation was never tapered to move water where it needs to go. TPO tolerates standing water far better than some materials, and it still is not what the seams and the warranty want. Ponding also concentrates dirt and accelerates the surface degradation.
- Heavy foot traffic. Every technician who services your HVAC equipment walks across the membrane, drops tools on it, and sets a condenser lid down on it. TPO is tough and it is not armor. Traffic pads and defined walkway paths from the roof hatch to every unit solve this, and skipping them is a decision you pay for around year six.
Thickness, honestly framed
TPO comes in mil thicknesses, and the numbers you will see on quotes are 45, 60, and 80. It is a durability ladder, and nothing more complicated than that.
Forty five mil is the thin end. It is a real product with real warranties behind it, and it suits a low-traffic building where nothing much is happening on the roof. Sixty mil is where most commercial work lands and it is what we specify by default, because the extra body handles the ordinary abuse of service techs and hail without much thought. Eighty mil is for roofs that take punishment: heavy equipment access, frequent servicing, buildings where a leak shuts down operations and the cost of being wrong is high.
The thicker membrane is not a different chemistry, it is more of the same material above the reinforcing scrim in the middle. That upper layer is the wear layer, and it is what stands between hail, foot scuffs, and the scrim that gives the sheet its strength. More wear layer means more margin.
Where the real difference shows up is hail, and North Texas has an opinion about hail. A thicker sheet over a solid substrate takes an impact that puts a thin sheet over soft insulation on the phone with us.
Repair, re-cover, or replace
These three words get used loosely and they mean very different amounts of money and disruption. Here is what each one actually involves.
A repair is targeted. A seam has opened, a puncture happened, a flashing at a curb has pulled loose. We clean the area back to sound membrane, cut a patch from matching material, and hot air weld it in with proper overlap. Done right, a welded patch is as strong as the field around it. This is the correct answer far more often than owners expect, and it is the answer that companies selling replacements are least interested in giving you.
A re-cover means a new membrane goes over the existing roof rather than removing it. It can be legitimate when the substrate below is dry and sound and the building code allows another layer. It is a much shorter job with less disruption to whatever happens inside. The hard requirement is that the insulation underneath is not wet, because a re-cover over saturated insulation seals the water in permanently and you have bought a very expensive delay. We core the roof and check before anybody proposes this.
A full replacement is tear-off to the deck, inspect and repair the deck, new insulation, new membrane, new details throughout. It is the right call when the insulation is wet across meaningful areas, when the deck needs attention, when the membrane has degraded generally rather than in spots, or when you are already at a second layer and code says no more. It is also the only path that resets the clock and comes with a full system warranty.
The way we decide between them is by getting on the roof and taking moisture readings and cores, then showing you the results. A moisture survey either finds wet insulation or it does not. That is a fact about your building, and it is not something we should be asking you to take on faith. Our commercial flat roof work starts there every time.
The maintenance rhythm that keeps your warranty alive
Here is what surprises owners more than anything else in this article. Most manufacturer warranties on a TPO system carry maintenance conditions, and a roof that has been neglected for six years can have a warranty that is technically void when you finally need it.
What the rhythm looks like in practice: an inspection twice a year, spring and fall, plus one after any serious hail or wind event. Drains and scuppers cleared so water leaves the roof. Debris removed, because a pallet band or a piece of angle iron left up there will eventually get walked on or blown into a seam. Seam and flashing checks at every penetration. Grease containment serviced on restaurant buildings on a much tighter schedule than twice a year. And documentation of all of it, because a warranty claim is a paperwork exercise and the records are what carry it.
Two hours on a roof in the spring is cheap next to a saturated insulation field. It is also the only version of this where you find problems on your schedule instead of during the first real storm of the season.
Common questions from commercial owners about TPO
Q. How long should a TPO roof last here? A properly installed system with reasonable maintenance has a long service life, and manufacturer warranties in the twenty year range are normal for a full system install. What actually decides it in North Texas is hail history, foot traffic discipline, and whether the drains stayed clear. Two identical roofs on two buildings can end up years apart on that basis alone.
Q. Can you patch TPO that is already ten years old? Usually yes. Weathered membrane needs to be cleaned and prepped properly before a patch will weld to it, and a crew that skips the prep gets a patch that lifts. Very old or heavily degraded membrane stops taking a reliable weld, and at that point we will tell you the repair is not worth your money.
Q. My roof has standing water two days after it rains. Is that a problem? It is worth addressing. Standing water by itself is not going to open a good seam tomorrow, and it points at something upstream: blocked drains, a sagging deck, or insulation that was never tapered correctly. It also shortens the life of everything it sits on. We would want to see where the water is holding and why before recommending anything.
Q. Is TPO the right material for a restaurant building? It can be, with the grease handled deliberately. That means containment at the hood curbs, protection in the drift zone downwind of the exhaust, and a service schedule that actually happens. Without those, grease will take the membrane apart around the units and the rest of the roof will look fine while it does.
Q. Do I need to shut the building down during a replacement? Almost never. We phase commercial tear-offs so that no open deck is left overnight and work moves in sections, and we schedule loud or disruptive stages around your operating hours where the building has any. Restaurants and warehouses have very different constraints and we plan around whichever yours are.
If you want somebody to get up on your building, take real moisture readings, and give you a straight answer on your roof rather than a sales pitch, call 817-789-0884 and ask for Seth. You can also send us the details of the building and we will get out there. We will tell you if it is a patch, and we will tell you that even when replacing it would have been better business for us.