TPO Roof Cost Calculator

What this calculator estimates

This calculator gives you a line-by-line 2026 US installed price for a TPO single-ply membrane roof. Whether you are re-roofing a 1,500 sq ft residential flat porch, replacing a 12,000 sq ft strip-mall roof, or specifying a 60,000 sq ft warehouse, the calculator follows the line-item structure that NRCA-member roofers use on real quotes:

• TPO membrane — 45-mil, 60-mil, or 80-mil, mechanically attached, fully adhered, induction-welded RhinoBond, or ballasted
• Tear-off — removing the existing membrane, insulation, and fasteners
• Polyiso (ISO) insulation — R-20, R-30, or tapered ISO for slope
• HD coverboard — DensDeck Prime, SECUROCK, or HD polyiso
• Drain count — internal drains and overflow scuppers
• Permit, disposal, weekend premium, and extra labour

A $1,650 minimum mobilisation fee applies in most US markets even on small jobs, because TPO requires a 2-person crew with a hot-air welder, induction welder (for RhinoBond), tracks, and a crane.

How to use it

1. Enter roof area in square feet (use the building footprint if the roof is flat).
2. Pick membrane thickness — 45-mil for light residential, 60-mil for commercial standard, 80-mil for premium warranty.
3. Pick attachment method — mechanically attached (baseline), fully adhered (+18%), induction-welded RhinoBond (+10%), or ballasted (−15%).
4. Pick polyiso insulation — none (recover), R-20, R-30, or tapered.
5. Set scope — spot repair (20%), partial replace (50%), or full re-roof (100%).
6. Set storey count — single-storey 1.0x, two-storey 1.18x, three-storey or higher 1.40x.
7. Set access difficulty — easy (drive-up) 1.0x, moderate (interior crane) 1.10x, hard (high-rise hoist) 1.30x.
8. Enter drain count and toggle tear-off, coverboard, permit, disposal, weekend premium, and any extra labour hours.

Typical 2026 US TPO roof cost ranges

These ranges reflect 2026 nationwide pricing from the NRCA Cost-of-Roofing Survey, SPRI Member Survey, and Q1 2026 quotes from Chicago, Dallas, Atlanta, Denver, Phoenix, and Newark.

Add 18 percent for two-storey, 40 percent for three-storey or higher. Add 10 to 30 percent for moderate to hard access. Add 25 percent for weekend or after-hours work.

Cost drivers

Membrane thickness and warranty tier. GAF EverGuard 60-mil is the workhorse for mid-market commercial. Holcim Elevate UltraPly 80-mil and Carlisle Sure-Weld 80-mil are specified for warehouses with maintenance traffic, hospitals, and where a 30-year non-pro-rated warranty is required for financing. The 80-mil cap layer is roughly 50 percent thicker than 60-mil and carries a 30 to 50 percent material premium, with labour cost similar.

Attachment method. Mechanically attached is the fastest install (4,000 to 6,000 sq ft per day for a 2-person crew) and the cheapest, but is prone to flutter under high wind and has visible fastener rows. Fully adhered (water-based or low-VOC bonding adhesive) is monolithic, has the best aesthetic on visible flat roofs, and the highest wind uplift, but costs 15 to 20 percent more and installs at 2,500 to 3,500 sq ft per day. RhinoBond eliminates the linear seam weakness while keeping mechanical-attachment speed. Ballasted is a legacy approach — fast on big roofs, but adds 12 to 16 lb per sq ft of dead load that the structure must accept.

Insulation and coverboard. Polyiso (PIR) is the dominant substrate. Two layers staggered prevent thermal bridging through joints. Coverboard (DensDeck Prime or SECUROCK Gypsum-Fiber) protects the TPO from polyiso facer punctures and is required by GAF, Carlisle, Holcim, and JM for 20+ year warranties. HD polyiso coverboard is a cheaper alternative used in lower-warranty tiers.

Tear-off versus recover. IBC 1511 permits up to two layers of roof covering before tear-off is required. Recovering an existing TPO or EPDM with new TPO is 25 to 35 percent cheaper than tear-off and reduces landfill volume. Tear-off is mandatory if the existing assembly is wet, water-damaged, or if a structural engineer requires deck inspection.

Drains and penetrations. Internal cast-iron drains (Wade, Watts, Jay R. Smith) are $320 to $480 each installed retrofit. Overflow scuppers, pipe boots, and HVAC curb flashings add $180 to $450 each. Reusing existing penetrations is cheaper than relocating but limits insulation slope design.

Storey, access, and crane logistics. A single-storey commercial roof with truck access is the cheapest install. Two-storey adds 18 percent for hoist time. Three-storey-or-higher adds 40 percent for tower crane or telehandler rental at $1,400 to $2,800 per day plus mobilisation. Interior crane through a roof hatch adds 15 to 25 percent for material handling.

TPO chemistry and what makes a good product

TPO (thermoplastic polyolefin) is a blend of polypropylene and ethylene-propylene rubber, reinforced with a polyester scrim. Quality varies between manufacturers based on:

• UV stabilisers: hindered amine light stabilisers (HALS) and UV absorbers extend cap-layer life. Lower-tier products fade and chalk within 8 to 12 years.
• Scrim weight: 800 to 1,500 denier polyester reinforcement. Heavier scrims resist puncture from foot traffic and hail.
• Plasticiser content: TPO uses no plasticisers (unlike PVC), so it does not embrittle over time the way old PVC membranes do.
• Carbon black masterbatch: white TPO is loaded with TiO2 (titanium dioxide) for UV reflection. Some lower-tier products use undersized TiO2 and fade faster.

For a 20+ year service life, specify a major manufacturer (GAF, Carlisle, Holcim, Versico, Johns Manville) with a 20-year NDL (no dollar limit) warranty.

US code references and authority sources

• IBC 1511 and IRC R908 — re-roofing and re-cover provisions
• IECC C402.1.3 (2024) — continuous insulation R-values by climate zone
• ASTM D6878 — TPO membrane standard, including thickness tolerances and reinforcement
• SPRI/ANSI RP-4 — wind design standard for single-ply membrane roofs
• FM Global 4470 / 4475 — wind uplift, fire, and hail performance approval
• UL 790 — fire-resistance Class A rating for steep and low-slope roofs
• NRCA Roofing and Waterproofing Manual — the industry installation reference, updated 2024
• CRRC (Cool Roof Rating Council) product directory — solar reflectance and SRI verification
• OSHA 29 CFR 1926.501 — fall-protection rules for roof work

When TPO is the wrong choice

• Steeper than 1/4:12 pitch with heavy snow load — water-shedding tile, metal, or modified bitumen with mineral cap may outperform.
• Deep-cold climates (-40°F design temperature) — EPDM or modified bitumen with SBS chemistry have better cold-temperature flex.
• Roofs with chemical exposure (kitchen exhaust, petrochemical) — PVC or KEE has better grease and chemical resistance.
• Mediterranean tile heritage zones — TPO is functionally fine but visually inappropriate; restoration with traditional materials is preferred.

Bidding strategy and red flags

Always get three written bids that itemise membrane brand, thickness, warranty tier, attachment method, insulation R-value, coverboard, and drain count. A bid that says “TPO roof, $X per sq ft” with no line items is a red flag. Confirm:

1. The bidder is on the manufacturer’s certified-applicator list (required for the 20+ year NDL warranty).
2. The bid includes wind-uplift testing documentation per ASCE 7-22 for your zip code.
3. The bid lists permit cost, disposal fees, and crane mobilisation as separate line items.
4. The bid includes a 2-year workmanship warranty on top of the manufacturer’s material warranty.
5. The bid identifies the foreman and crew certification.

For deeper estimating, also use our flat roof replacement cost calculator, built-up roof cost calculator, and roof coating cost calculator to compare TPO against the alternatives at your specific square footage and climate zone.