If you own a low-slope commercial building in Dallas, Fort Worth, or anywhere across North Texas, a TPO (thermoplastic polyolefin) overlay is one of the fastest, most cost-effective ways to add another 20+ years to your roof — without the disruption, dumpster fees, or tear-off labor of a full replacement. This guide covers when an overlay qualifies, how we install it, and the numbers Texas property owners should expect.
What is a TPO overlay?
A TPO overlay is a single-ply white membrane installed directly over your existing low-slope roof system — typically over an aged BUR (built-up roof), modified bitumen, or an older TPO/EPDM membrane that is still structurally sound. Instead of stripping the building down to the deck, we add a new insulation layer (or a recovery board), mechanically fasten or adhere the new TPO, and heat-weld every seam into a continuous, reflective, watertight surface.
When an overlay qualifies — and when it doesn't
- The existing roof has fewer than two roof systems on it already (IBC limit for Texas commercial).
- The deck and structure are dry, sound, and free of widespread saturation.
- No more than ~25% of the existing membrane shows active leaks or wet insulation (we core-sample to confirm).
- Slope and drainage are adequate — ponding water deeper than 1" 48 hours after rain usually means tear-off, not overlay.
If any of those fail, we recommend a tear-off. Putting new membrane over wet insulation just buys you a more expensive failure two years from now.
The cost case for Dallas / Fort Worth owners
On a typical 20,000 sq ft North Texas warehouse, we see overlay pricing land 30–50% below a comparable tear-off and replace — usually $4.50–$7.00 per sq ft installed for a 60-mil TPO overlay vs. $9–$13 per sq ft for a full tear-off. The savings come from three places:
- No tear-off labor, no dumpsters, no disposal fees (Texas commercial landfill fees keep climbing).
- Existing insulation stays in place — you're only adding R-value, not buying all of it new.
- Crews stay productive in heat; no exposed deck means tenants and operations keep running.
Energy and ESG upside (the part the CFO will care about)
TPO's bright-white reflective surface carries a high SRI (Solar Reflectance Index). On a Texas summer afternoon, a freshly installed white TPO membrane runs 50–70°F cooler than the aged black BUR underneath. We routinely see 10–20% reductions in summer HVAC load on retrofit projects in Dallas and Fort Worth — measurable on the utility bill within the first cooling season. The membrane also qualifies for ENERGY STAR and most LEED reflectance credits.
How we install a TPO overlay in Texas
1. Core sample + moisture survey. We pull cores in a grid across the roof and use infrared (after sunset) to map any wet insulation. Wet areas get cut out and replaced before the overlay goes down — non-negotiable.
2. Surface prep. Loose gravel, blisters, and ridges get knocked down. Drains and curbs get reflashed. The existing membrane must be smooth enough that the new system sits flat.
3. Recovery board or new ISO. Depending on the substrate, we install a 1/2" HD coverboard or add a layer of polyiso insulation to bring R-value up to current Texas energy code (R-25+ for the 2021 IECC zones that cover most of the state).
4. TPO membrane. 60-mil minimum for commercial. We hot-air weld every seam — no tape, no caulk — and probe-test every weld before sign-off.
5. Flashings and details. Pipe boots, curbs, parapets, and edge metal all get new TPO-coated flashing or factory-fabricated accessories. This is where 80% of overlay failures happen industry-wide; we don't cut corners here.
6. Manufacturer inspection + warranty. For 15- and 20-year NDL (No Dollar Limit) warranties, the manufacturer sends a field inspector before the warranty issues. We schedule that walk before our final invoice.
Warranty: what you actually get
Most of our Dallas / Fort Worth commercial overlay projects ship with a 20-year NDL manufacturer warranty plus a 5-year Hale Yeah workmanship warranty. The NDL warranty means the manufacturer covers material AND labor with no per-claim cap — that's the only warranty tier worth specifying on a building you plan to hold. A standard 15-year material-only warranty is usually a sign someone cut a corner on details.
A real Texas project: 38,000 sq ft Fort Worth distribution facility
Original roof: 18-year-old modified bitumen, three patched leaks, ponding around two drains, R-13 insulation. Owner had two tear-off bids at $11.20 and $12.80 per sq ft. We core-sampled, confirmed <8% wet insulation, cut out and replaced those sections, added 2" of polyiso (R-25 total), and installed a 60-mil mechanically-fastened TPO overlay. Final price: $6.10 per sq ft, 22-day install, zero operational downtime, 20-year NDL warranty. Owner's first summer HVAC bill dropped 14% year-over-year.
What to ask any contractor bidding your overlay
- Can I see the core-sample report and the moisture-survey map?
- What's the proposed insulation thickness, and what R-value does that put the assembly at?
- Mechanically-fastened or fully-adhered? (Fastened is faster and cheaper; adhered is quieter and better for wind uplift in coastal counties.)
- What membrane thickness — 45-mil, 60-mil, or 80-mil? Spec 60-mil minimum for commercial in Texas.
- 15-year material warranty or 20-year NDL? Get the NDL spec in writing.
- Who's doing the heat-welding, and how many years has that crew been on TPO?
Ready to find out if your building qualifies?
Every commercial overlay we quote starts with a free roof survey — drone imagery, core samples on larger buildings, and a written report you can hand to your asset manager or insurance carrier. If the building doesn't qualify for an overlay, we'll tell you that too, and price the tear-off honestly. Either way, you get a documented baseline of where the roof stands today.