Low-slope roofs carry most of Houston's businesses
Commercial roofing in Houston is mostly low-slope roofing: wide, nearly flat surfaces covered by a continuous membrane instead of overlapping shingles. The Whole Building Design Guide defines a low-slope roof as one with a pitch of 3 in 12 or less, and almost every strip center, office park and warehouse along the Beltway fits that description.
Those roofs fail differently from a house roof. Water does not run off quickly, so it finds open seams, clogged drains and cracked flashing around the equipment that sits on top. A small opening can wet a large area of insulation before anyone inside sees a stain on a ceiling tile.
Houston Expert Roofers does no roofing work. The number is a no-cost referral line. Day or night, its automated assistant asks about the building and the problem, then puts you through to an independent roofing company that takes commercial jobs. That company walks the roof, quotes and does the work.
The low-slope systems on Houston buildings
Property owners hear a string of acronyms when roofers start talking. This is general product information, so you can follow the conversation. It does not recommend one system over another; the right choice depends on the building, its deck, its drainage and the budget.
| System | What it is | How seams are joined | Questions worth asking |
|---|---|---|---|
| TPO | A single-ply thermoplastic sheet laid in wide rolls over insulation | Heat-welded with hot air | What thickness, and will it be fully adhered or mechanically fastened? |
| PVC | A single-ply thermoplastic sheet, a close relative of TPO in how it is installed | Heat-welded | Is the membrane suited to any grease or chemical exhaust that reaches this roof? |
| EPDM | A single-ply synthetic rubber sheet | Adhesive or seam tape | How will the seams be primed and taped, and what is the plan at penetrations? |
| Modified bitumen | Asphalt sheets modified with polymers, applied in one or more plies, sometimes with a granule surface | Torch, hot asphalt, cold adhesive or self-adhered laps | Will any torch work happen on this building, and what is the fire watch plan? |
| Built-up roofing | Several layers of roofing felt and asphalt, sometimes topped with gravel | Layered in place | Is the gravel being reused, and can the deck carry the weight? |
| Metal panels | Standing seam or through-fastened steel panels on low-slope or pitched framing | Seamed or lapped and screwed | Which uplift test does the panel carry, and at what clip spacing? See metal roofing. |
| Fluid-applied coatings | Acrylic, silicone or other coatings rolled or sprayed over an existing sound roof | Seamless once cured | What thickness, what warranty, and what tests showed the roof underneath is dry? |
Single-ply membranes such as TPO, PVC and EPDM can be fully adhered, mechanically fastened or ballasted with stone, according to roofing training material from the State of Connecticut's construction services department. The attachment method affects how the roof resists wind, so it belongs in the written proposal.
What goes wrong on business roofs in this climate
Water that will not leave
NRCA treats a roof as properly sloped when no water is left standing 48 hours after rain in drying weather. Standing water beyond that is ponding. It adds weight, keeps seams wet and points to a low spot, a sagging deck or a blocked drain.
Drains, scuppers and gutters
Leaves, packaging, bird nests and loose gravel collect at roof drains. A blocked primary drain sends water toward the overflow scuppers or over the parapet, and the water left behind loads the roof.
Rooftop units and curbs
Air conditioning units, exhaust fans and vents sit on curbs that are flashed into the membrane. Foot traffic to and from those units, dropped screws and tools, and panels left off can all damage the membrane around them.
Seams and edges in the wind
Wind lifts a membrane first at its edges and corners. Loose metal edging or coping lets air get under the sheet, and a seam that was weak from the start opens further each storm.
Wet insulation
Water that gets under the membrane soaks the board insulation and stays there. Wet insulation loses its value, adds weight and can rot a wood deck or rust a steel one. It also limits whether a coating or recover is possible.
Heat and sun
Dark roofs run far hotter than light ones. ENERGY STAR cites Lawrence Berkeley National Laboratory: on a summer afternoon a clean white roof reflecting 80 percent of sunlight stays about 50 degrees Fahrenheit cooler than a gray roof reflecting 20 percent.
How a careful roofer handles a commercial job
- A roof walk and an interior check. Seams, flashing, curbs, drains, edges and the underside of the deck where it is visible, with the leak history from tenants or maintenance staff.
- Finding out how wet the roof is. On a roof of any size, the roofer should tell you how it measured moisture under the membrane and show the results on a roof plan.
- Options in writing. Repair, coating, recover over the existing roof or a full tear-off, each with its scope, its warranty and what it assumes about the deck and insulation.
- A plan for the occupants. Working hours, crane or lift locations, odors from adhesives or torch work, noise, parking, and who tells the tenants.
- Permit, inspections and closeout. The permit pulled in the roofer's name, inspections passed, and a closeout file with photos, the manufacturer's warranty if one applies and the workmanship warranty.
Houston Expert Roofers' own part ends at the phone call: it answers, asks a few questions about the building and connects you. Everything on this list is between you and the roofing company.
Commercial roofing permits in Houston
Inside the City of Houston, a new roof or an overlay on a commercial structure needs a commercial roofing permit (Houston Permitting Center code HPWCODE1157). The city lists plan review and inspection as required, a processing time of about 10 business days and a permit that stays valid for six months. The application includes a building permit application and either the Commercial Re-Roof Only Worksheet (CE-1076) or the roofing overlay worksheet (CE-1104), plus plans where they apply. Depending on the scope, the structural, planning, fire marshal or floodplain groups may also need to approve it, and the permit, worksheet and plans must stay on site for the inspector.
Insulation matters to the permit as well. The city's re-roofing permit guidance asks for an energy code software report with a completed COMcheck inspection checklist whenever the insulation above the deck changes. Ask the roofer, before you sign, whether the job will touch the insulation and how that affects the permit and the price.
Suburban cities such as Sugar Land, Pearland, League City and Baytown run their own building departments with their own rules, so the roofer should confirm the local requirement in writing. The service areas page links to each town page.
Buildings on the coast
Commercial buildings near the bay follow the same windstorm rules as homes. The Texas Department of Insurance says a commercial structure that will be insured for wind and hail through the Texas Windstorm Insurance Association must at minimum meet TDI's adopted building standards, and TWIA counts repairs, including reroofing, among the improvements that need certification. TDI's product evaluations for metal roof panels require uplift testing to a recognized standard such as UL 580 or UL 1897.
Coastal windstorm rules. In the Texas Department of Insurance's designated catastrophe area (Brazoria, Chambers, Galveston and the other first-tier coastal counties, plus, in Harris County, Morgan's Point and the parts of La Porte, Pasadena, Seabrook and Shoreacres inside city limits and east of State Highway 146), most roof work must meet the windstorm building code and be inspected while it is under way (TDI exempts repairs to less than 100 square feet of roof covering that do not touch the decking). When it passes, TDI issues a certificate of compliance (form WPI-8), which the Texas Windstorm Insurance Association uses to decide whether it can insure the home. Ask the roofer, in writing, who schedules the inspection and when you will get the WPI-8.
Tell the line what kind of building it is, roughly how big the roof is and what is happening (a leak over a tenant, ponding, storm damage or a roof near the end). The local roofing company you are put through to walks the roof and gives you its own written proposal.
Questions for owners and property managers to ask
About the roof and the proposal
- How did you check for wet insulation, and where is it wet on the roof plan?
- Why this system and this attachment method for this building?
- What happens at each drain, curb, edge and wall in the scope?
- Does the manufacturer's warranty require its own inspection, and who pays for it?
- How will rooftop units be disconnected, lifted or protected, and who calls the mechanical contractor?
About the company and the site
- Can you send a certificate of liability insurance and proof of workers' compensation coverage, naming my company as certificate holder?
- Will you pull the permit, and who schedules the inspections?
- What hours will you work, and how will tenants, parking and deliveries be handled?
- Where will materials, the dumpster and any crane go?
- What maintenance plan do you suggest after the job, and what does it cost per visit?
If a storm damaged the roof and the building is insured, read the roof insurance claims guide. The policyholder files the claim, and Texas law limits what a roofer may do in that process.
Keeping a commercial roof working between projects
Most low-slope roofs that fail early do so from neglect rather than a single storm. NRCA's recommendation of an inspection at least twice a year, preferably spring and fall, plus a look after any hurricane, tornado or hailstorm, fits Houston well: spring comes before the worst of the thunderstorm and hurricane season, and fall shows what that season did.
- Keep drains, strainers and scuppers clear, especially under trees and after storms.
- Limit roof access to people who need to be there, and log who goes up.
- Ask mechanical contractors to report any damage they cause or see.
- Keep the warranty, drawings and every inspection report in one file.
- Fix small seam and flashing problems while they are small; wet insulation is what turns a repair into a replacement.
The May 16, 2024 derecho brought winds over 100 mph to parts of the Houston area, according to the National Weather Service Houston/Galveston office. Hurricane Beryl followed on July 8, 2024. Many commercial roofs took debris and edge damage that year. If your building has not had a roof inspection since then, it is worth one.
How a commercial roofing call works
- Call the numberAn automated assistant answers (832) 662-4107 at any hour and asks which service you need, since the line also takes heating, cooling, pressure washing and water damage calls.
- Describe the roofA leak, missing shingles, hail, a limb on the roof or an old roof you want looked at, plus your part of greater Houston and how urgent it is.
- Get put throughYour call is transferred to an independent, locally owned roofing company, which hears a short summary before it picks up.
- Deal with the roofer directlyIt inspects, quotes and does the work, and you pay it (or your insurer does, as you arrange). If it misses the call, it gets your name, number, city and need to call you back.
Texas has no state roofing license. No state agency licenses roofing contractors in Texas, and a 2025 bill to create one (HB 3344) did not reach a vote of the full House before the session ended. So check what you can: a certificate of liability insurance sent to you, a written contract with the full scope, a permit where your city requires one, local addresses you can drive past, and the shingle maker's warranty registration. Some cities also ask roofers to register. The line does not check any of this for you. How to check a roofer before you hire.
The deductible is yours to pay. The Texas Department of Insurance says it is illegal for a contractor to offer to waive, rebate or absorb your deductible, and a contract of $1,000 or more paid with insurance money must include a notice saying so. A roofer also may not act as your public adjuster on a property it works on. Treat any offer to "cover the deductible" as a reason to call someone else.
About this line: Houston Expert Roofers is a free phone line, not a roofing contractor. It answers your call and connects you with an independent local roofing company, which inspects, quotes and does the work, and which you pay directly. Companies may pay a referral fee. The line never charges you. Read how the line works.
Related services
- Flat Roof Repair
- Metal Roofing in Houston
- Roof Inspection in Houston
- Storm Damage Roof Repair
- Roof Leak Repair
- Roof Insurance Claims in Texas