A TPO roof is a single sheet of white synthetic membrane laid over a flat or low-slope roof. TPO stands for thermoplastic polyolefin. The sheets are welded together with hot air, so the whole roof becomes one piece. Drive past any strip mall or warehouse in Columbia and you’ve probably seen one.
What is TPO made of?
TPO is rubber blended into plastic. Holcim, one of the big membrane makers, describes it as “ethylene propylene rubber into a thermoplastic matrix of polypropylene” (Holcim UltraPly TPO FAQ). The rubber lets it flex. The plastic lets it melt and weld.
It isn’t new. TPO membranes became commercially available in the U.S. in the early 1990s (Professional Roofing, February 2014). So we’ve got three decades of roofs to judge it by.
It also skips plasticizers, the additives that can migrate out of some membranes over the long term (Holcim). Our own commercial roofing page notes TPO has no chlorine or dioxins.
How does a TPO roof go on?
In wide rolls, fastened or glued to insulation board. Then a crew welds every overlap with an automatic hot air welder (Holcim). The two sheets melt into each other.
That weld is the whole roof. A bad one, welded too cold or over dirt, is where leaks start. So ask any contractor how they test seams before they leave. A good crew probes every one.
Why do so many flat roofs in Columbia use TPO?
Because it’s white, and our summers are hot. Columbia’s average July high is 92.7°F (NOAA 1991-2020 normals).
A dark flat roof soaks that up all afternoon. A white membrane bounces most of it back. Duro-Last says plainly that “highly reflective white membranes save on energy costs” (Duro-Last). Researchers writing in Professional Roofing found TPO roofs normally stay under 130°F at the surface (McGroarty and Taylor, Professional Roofing, 2014). A cooler membrane ages slower.
Is TPO the only answer? No. EPDM, the black rubber membrane, is still a good roof. We install both. If you’re weighing them, our TPO roofing contractors will walk you through it on your actual building.
Is all TPO the same?
No, and it’s the first thing to ask about. TPO comes in 45, 60 and 80 mil thicknesses (Duro-Last). Thicker is tougher.
The same study split TPO into three grades. Utility grade was projected at 15 years. Standard grade at 25. Heavy grade, built for demanding roofs, at more than 35 (Professional Roofing, 2014).
So “we’ll put TPO on it” isn’t a full answer. Ask which thickness. Ask the warranty length too. Manufacturers write 15-year to 25-year no-dollar-limit warranties on TPO (Duro-Last). The longer warranty usually means the better sheet.
Where does TPO fall short?
Mostly where people walk and where water sits. A dropped tool or a careless HVAC tech can puncture it. Clogged drains leave water standing in the sun, working at the seams.
Seams themselves hold up when they’re welded right. A field study of 60-mil TPO installed in 2000 and 2001 found “no issues with seam integrity, membrane tightening or overall watertightness” (Western States Roofing Contractors Association, cited in Professional Roofing). Install quality decides most of it.
Is TPO right for your building?
If it’s flat or low-slope and commercial or multi-family, probably. Most Midlands houses have pitched roofs, so homeowners mostly see TPO on a flat porch or addition.
The Red Shirt Guys are veteran-owned and have worked Columbia roofs for 20+ years. We do commercial flat roof replacement and apartment and condo roofing built around the people inside. The estimate is free. Call 803.243.3968 or request a free estimate.
FAQ
What is a TPO roof made of? Ethylene propylene rubber blended into polypropylene plastic (Holcim). The rubber flexes and the plastic welds.
What is a TPO roof’s lifespan? It depends on the grade. Published projections run 15 years for utility grade, 25 for standard and more than 35 for heavy grade (Professional Roofing, 2014). Our FAQ notes commercial roof lifespans vary a lot.
Is a TPO roof the same as a rubber roof? Not quite. “Rubber roof” usually means EPDM, the black membrane. TPO is white, and its seams are heat-welded with hot air (Holcim).
Can a TPO roof go on a house? Yes, on flat or low-slope sections. It’s built for those roofs, not for a steep pitched roof.
What color is a TPO roof? Usually white, because white reflects the sun. Duro-Last calls its white sheet “highly reflective” (Duro-Last).
Not sure what your roof needs?
Get a free, no-pressure roof inspection from The Red Shirt Guys.
Request a free inspectionor call 803-243-3968