"Had a persistent leak on my flat garage roof for two years. Two other contractors patched it and it kept coming back. Ranlock diagnosed the real problem, installed a proper TPO system, and it's been bone dry through three big storms since."
Houston's heat, UV exposure, and heavy rainfall demand a flat roofing system that doesn't quit. Ranlock installs TPO single-ply membrane and torch-down modified bitumen systems engineered for long-term waterproofing performance on flat and low-slope roofs across Greater Houston.
Both are proven performers in Houston's climate. We'll help you choose the right one for your building type, budget, and long-term goals.
Thermoplastic Polyolefin (TPO) is the most popular flat roofing membrane in North America — energy-efficient, heat-weldable, and ideal for Houston's intense UV and heat load.
Modified Bitumen torch-down roofing is a time-tested asphalt-based system applied with a propane torch. Exceptional waterproofing, puncture resistance, and impact durability — trusted for decades in Texas.
Not sure which system is right for your property? Here's the complete breakdown. We'll give you our honest recommendation during your free inspection.
| Feature | TPO Membrane | Torch-Down Modified Bitumen |
|---|---|---|
| Best For | Commercial, large flat roofs, energy-efficiency priority | Residential flat, low-slope, complex geometry roofs |
| Material | Single-ply thermoplastic membrane | Asphalt-based modified bitumen sheets |
| Installation Method | Mechanically fastened or fully adhered, heat-welded seams | Propane torch heat-fused to substrate |
| Seam Strength | Very strong — heat-welded monolithic bond | Excellent — fully bonded, no exposed seam edges |
| UV Resistance | Outstanding — white reflective surface Best for Heat | Good — granulated cap sheet provides UV protection |
| Energy Efficiency | High — reflects solar heat, reduces AC load Energy Star | Moderate — granulated surface absorbs more heat |
| Puncture Resistance | Good | Excellent — multi-ply asphalt layers are very tough |
| Waterproofing | Excellent with properly welded seams | Excellent — seamless adhesion eliminates common leak points |
| Ponding Water Tolerance | Good | Very good |
| Typical Lifespan | 20–30 years | 15–25 years |
| Repairability | Easy — patch with heat welder | Easy — torch or cold-applied patch |
| Relative Cost | Moderate to higher (larger commercial) | Moderate — economical for residential |
| Houston Climate Fit | ⭐⭐⭐⭐⭐ — Excellent heat & UV performance | ⭐⭐⭐⭐⭐ — Proven decades of TX performance |
We'll inspect your roof, assess slope, drainage, and use case, and give you an honest recommendation — free.
Flat and low-slope roofing systems are more common than most Houston homeowners realize. Here's where Ranlock installs TPO and torch-down systems.
Modern and contemporary Houston homes with flat or low-slope roof sections. Also common on back additions, garage-top rooms, and covered entries.
Retail stores, strip centers, warehouses, office buildings, restaurants — virtually all commercial flat roofs in Houston are ideal candidates for TPO systems.
Attached patio covers, awnings, and low-slope canopy structures. Torch-down is an excellent waterproofing solution for residential outdoor structures.
Room additions, sunrooms, and second-story pop-outs often feature low-slope rooflines where a flat roofing membrane is the right technical solution.
Detached garages, carports, and workshop structures with flat roofs. Torch-down provides economical, reliable waterproofing for these structures.
If your flat roof was damaged by a hurricane, tropical storm, or severe weather event, we handle insurance documentation and complete system replacement.
Whether you choose TPO or torch-down, every Ranlock flat roof installation follows the same careful process — no shortcuts, no skipped steps.
We inspect your existing flat roof, assess slope, drainage, deck condition, and identify any ponding, leaks, or structural concerns. Completely free.
You get a detailed, itemized quote including material specs, labor, drainage improvements, and warranty terms — with a clear recommendation between TPO and torch-down.
Full removal of existing roofing layers. Decking is inspected, dried, and any damaged sections are repaired or replaced before the new system goes down.
Proper insulation board, membrane or bitumen installation, flashing of all penetrations, HVAC curbs, and drains — every detail executed to manufacturer spec and local code.
Flat roofs fail quietly — often for months before an interior leak makes itself known. Watch for these warning signs and call Ranlock for a free inspection if you spot any of them.
Water that stands on your flat roof for more than 48 hours after rain indicates a drainage problem. This accelerates membrane breakdown and adds significant structural load.
Blisters on a flat roof membrane indicate trapped moisture or air beneath the surface. Left untreated, they burst and create open leak points.
An alligator-skin cracking pattern on torch-down or older built-up roofs means the asphalt has dried out and lost its flexibility — full replacement is typically needed.
Lifted seams, open laps, or edges pulling away from the parapet wall are the #1 source of flat roof leaks. These require immediate attention before water infiltrates.
Water stains on ceiling tiles, drywall, or insulation below a flat roof mean water has already penetrated. A full inspection is urgently needed to find and stop the source.
Even a well-maintained flat roof approaching the end of its design life should be proactively evaluated. Replacement before failure prevents interior damage and emergency costs.
Greater Houston averages over 50 inches of rain per year — among the highest of any major US city. Flat and low-slope roofs in our market face challenges that don't exist in drier climates:
"Had a persistent leak on my flat garage roof for two years. Two other contractors patched it and it kept coming back. Ranlock diagnosed the real problem, installed a proper TPO system, and it's been bone dry through three big storms since."
"Ranlock replaced the torch-down roof on our retail building in Pasadena. Competitive price, explained everything clearly, and the crew worked around our business hours. No water intrusion since — very pleased."
"My home addition has a low-slope section that had been leaking since we bought the house. Ranlock installed a new TPO system with proper drainage and re-flashed the connection to the main roof. Problem solved, completely."
Not sure if your flat roof needs repair or full replacement? Tell us about your property and we'll come out, inspect it thoroughly, and give you an honest written quote — at no charge and no obligation.
Flat roof inspection, repair, or replacement — we'll respond within 2 hours.
TPO or torch-down — we'll inspect your flat roof, diagnose the problem, and give you a transparent quote on the right system for your property. Free, fast, no obligation.