How much does it cost to fix a commercial roof?

Most single commercial roof repairs cost about $300 to $3,500: a membrane patch, a seam, a flashing at a rooftop unit or a drain. Repairs that involve wet insulation, long seam runs or storm damage across the roof typically run $5,000 to $25,000 or more. Access, the roof system and whether a manufacturer warranty is in force all move the price.

Who is responsible for roof repairs in a commercial lease?

The lease decides. Read the repair, maintenance and capital-expenditure clauses: many net leases pass routine roof maintenance to the tenant while the landlord keeps responsibility for the structure and replacement, but terms vary widely. Report leaks to the landlord in writing either way, because a manufacturer warranty usually needs prompt notice.

Where do flat roofs leak most?

Flat roofs leak most at seams, at flashings around rooftop units, pipes and vents, at parapet walls and edge metal, and at drains and scuppers. Water that ponds near these details finds the weak point first, which is why leaks inside often appear some distance from the actual hole.

Why does my flat roof leak in heavy rain?

Heavy rain overwhelms whatever is already marginal: clogged or undersized drains back water up over flashings, ponding water sits on seams, and wind-driven rain gets behind loose edge metal or wall flashing. If a roof only leaks in downpours, check drainage and flashing heights before patching the membrane.

How do you repair a TPO or EPDM roof?

TPO and PVC are repaired by cleaning the area and hot-air welding a patch of matching membrane over the damage. EPDM is cleaned, primed and patched with EPDM tape or a pressure-sensitive patch, because rubber membranes are joined with tape or adhesive rather than heat. In both cases, wet insulation under the damage has to come out first. See our TPO roofing guide for how the membrane is built.

When should a commercial roof be replaced instead of repaired?

Replace when a moisture survey finds widespread wet insulation (many contractors treat about a quarter of the roof area as the tipping point, an industry rule of thumb, not the Florida building code’s 25% repair rule), when the membrane is brittle or shrinking, or when leaks keep returning after repairs. Our commercial roof replacement cost guide shows what the alternative costs.

Does insurance cover hail damage on a commercial roof?

Commercial property policies usually cover sudden damage from hail and wind, subject to the deductible and the policy's roof terms. Check whether the roof is covered at replacement cost or actual cash value (which deducts depreciation), report the loss promptly, document the damage with dated photos, and make temporary repairs to prevent further damage.

Will a repair void my roof warranty?

It can. Manufacturer system warranties typically require repairs and alterations to be done by an applicator the manufacturer has approved and reported to the manufacturer. A patch by an unapproved roofer can void coverage on the whole roof, so check the warranty before anyone works on it.

Commercial Roof Repair: Costs, Common Leaks & Quotes

Common commercial and flat roof problems

Many commercial roof leaks start at the details, not in the open field of the membrane: seams, flashings, drains and the curbs under rooftop equipment. Common problems include:

Ponding water. Water still standing 48 hours after rain is ponding; the code's "positive drainage" standard uses the same 48-hour test. It loads the deck, ages the membrane faster and finds any weak seam.
Seam failures. Laps that were under-welded on TPO or PVC, or tape and adhesive seams on EPDM that have let go with age.
Membrane punctures. Foot traffic from HVAC service, dropped tools, debris and hail.
Flashing and penetrations. Base flashing at parapet walls, pipe boots, vents and edge metal that have pulled loose or cracked.
Blistering. Bubbles in modified bitumen and built-up roofs where air or moisture is trapped between plies.
HVAC curb leaks. Rooftop units get serviced, moved and replaced, and the curb flashing around them is a frequent leak source.
Clogged drains and scuppers. Leaves and debris back water up over flashings during heavy rain.

How repairs differ by roof system

The repair method follows the membrane: thermoplastics are welded, rubber is taped, and asphalt systems are patched with new plies. Using the wrong material, or an unapproved roofer, can void a manufacturer warranty.

TPO and PVC: the area is cleaned and a patch of the same membrane is hot-air welded over the damage. Failed seams are re-welded or covered with a welded strip. Older, dirty membrane needs more preparation before a weld will hold. See our TPO roofing guide.
EPDM: rubber membranes are joined with seam tape or adhesive, so repairs use a cleaned and primed area with an EPDM patch or pressure-sensitive tape.
Modified bitumen: blisters and splits are cut out and covered with new cap sheet, torch-applied, cold-adhered or self-adhered to match the existing system.
Built-up roofing (BUR): damaged plies are cut out and replaced with felts and asphalt, and the gravel surfacing is restored over the patch.

Whatever the system, wet insulation under a leak should be cut out and replaced. A patch over soaked insulation keeps the water in the roof, where it rots decks and rusts fasteners.

Commercial roof repair costs

A typical single repair costs a few hundred to a few thousand dollars, and the minimum charge for getting a crew and equipment on the roof is a big part of small jobs. Here are typical 2026 ranges by repair type.

Prices reviewed October 2026

Repair	Typical cost	Notes
Small membrane patch (puncture or tear)	$300–$1,500	Mostly trip charge and minimum labor
Seam repair, short run	$300–$1,200	Re-weld or cover strip on a single failed lap
Seam reseal, 50–200 linear feet	$1,800–$7,500	Scales with length; long runs point to replacement
Flashing at a curb, pipe or vent	$500–$2,500 each	Rooftop units and penetrations are top leak sources
Drain or scupper repair	$400–$2,000	More if the deck around the drain has rotted
Modified bitumen repair	$1,000–$4,000	Cutting out blisters and splits, adding new cap sheet
Emergency temporary leak stop	$400–$2,000	A bridge until the permanent repair
Wet insulation removal and replacement	$2,500–$15,000	Depends on the wet area found by a survey
Storm damage or multiple leaks	$5,000–$25,000+	Often worth an insurance and warranty review

How we estimate these costs: ranges are compiled from published 2026 industry cost data and typical commercial contractor pricing across U.S. markets. We are not a contractor and do not set prices. High-cost metros, difficult access and warranty requirements push costs toward the top.

What drives the price:

Access. Roof height, interior-only roof hatches and the need for a lift or crane add labor and equipment time.
Hidden moisture. Wet insulation found under a leak turns a patch into a tear-out.
Number of details. Each rooftop unit, pipe and drain is its own flashing job.
Warranty terms. If the roof is under a manufacturer warranty, the repair must meet that manufacturer's specification and may need an approved applicator.
Timing. Emergency calls after hours or during a storm cost more than scheduled work.

For residential repairs, see our separate roof repair page.

Emergency leak response

When a commercial roof leaks during a storm, protect people and contents first, then get a temporary repair, and only then the permanent one. Keep everyone off the roof until the weather passes.

Move inventory, equipment and people away from the leak and contain the water.
Photograph the interior damage and note the time and weather.
Call a roofer for a temporary repair once it is safe; our emergency roof repair page explains what that involves.
Notify the roof's manufacturer or warranty holder in writing; one major manufacturer's warranty requires notice within 30 days.
Notify your insurer if storm damage is likely, and keep every invoice.

When repair stops making sense

Repair stops making sense when moisture or age has spread through the roof rather than sitting in one spot. The way to know is a moisture survey, not a guess.

An infrared survey (the method in ASTM C1153) finds wet insulation because it holds heat after sunset; nuclear and capacitance meters are alternatives, and core cuts confirm what any of them find. Many contractors treat roughly a quarter of the roof area being wet or damaged as the point where replacement beats repair or coating. That is an industry rule of thumb, not a building code requirement, and it is separate from the Florida Building Code’s 25% repair rule. Other signs are a brittle or shrinking membrane, seams failing across the roof, and repair bills that come back every season.

A roof that is dry and well attached but worn may be a candidate for a coating restoration (see restoration costs). A roof with widespread wet insulation needs that insulation removed: the International Building Code does not allow re-covering a water-soaked roof. See commercial roof replacement costs to compare.

Insurance for storm and hail damage on commercial roofs

Commercial property insurance generally covers sudden damage from hail, wind and falling objects, not wear and tear, and the roof terms in your policy decide how much it pays.

Check whether the roof is insured at replacement cost or actual cash value, which subtracts depreciation for the roof's age.
Check the wind and hail deductible and any deadline for reporting a loss.
Document damage with dated photos and a written inspection report before repairs begin, and make temporary repairs to stop further damage.
Read your manufacturer warranty too: some cover hail up to a stated stone size, and they still require approved repairs.

Our storm damage repair guide covers the claim process in more detail.

Commercial roof repair: costs, common leaks and fixes

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