How much does flat roof repair cost?
Ashburn, VA

How much does flat roof repair cost?

Ashburn, VA

How much does flat roof repair cost?

$2.50 – $10.00cost per square foot installed
$300 – $1,100average cost to repair

Get free estimates for your project or view our cost guide below:

$2.50 – $10.00 cost per square foot installed

$300 – $1,100 average cost to repair


Get free estimates for your project or view our cost guide below:
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Jennifer Carlson
Written by
Jennifer Carlson
Edited by
Kristen Cramer
Fact-checked by
Tom Grupa

Flat roof repair cost

Flat roof repair costs $2.50 to $10.00 per square foot or $300 to $1,100 on average, depending on the material and extent of damage. Flat roof leak repair costs $500 to $1,200 on average. Consider replacing flat roofs older than 10 years for $3 to $11 per square foot.

Flat roof repair cost - chart
Flat roof repair cost - chart
Average flat roof repair cost
National average cost $900
Minimum cost $100
Maximum cost $5,000
Average range $300 to $1,100

Get free estimates from roofing companies near you.

Flat roof repair cost estimate by type

Flat roof repair costs by type
Repair Average cost
Leak repair $500 – $1,200
Coat / reseal / recover $500 – $2,000
Tear off and full replacement $4,000 – $16,800

Flat roof leak repair cost

Flat roof leak repair costs $150 to $500 for minor sealing or $500 to $1,200 to replace and seal the roofing. Repairing extensive leaks and structural damage costs $1,200 to $3,000. Small roof leaks can eventually cause structural issues if left unresolved.

Flat roof leak repair cost
Leak Size Average cost Repairs
Small $150 – $500
  • Sealant applied to small cracks or loose roofing
  • No water-damaged roofing
Average $500 – $1,200
  • Multiple leaks
  • Membrane replacements and sealing
  • Multiple roofer visits
Large $1,200 – $3,000
  • Multiple leaks with extensive damage
  • Repairing water-damaged rafters and roofing
  • Multiple roofer visits

Contractor sealing and repairing flat roof
Contractor sealing and repairing flat roof

Cost to coat or reseal a flat roof

Sealing or coating a flat roof costs $1 to $4 per square foot or $500 to $2,000 on average, depending on the roof material, sealant type, and job complexity. Resealing increases a roof’s lifespan.

Cost to coat or seal a flat roof
Roof size (square foot) Average cost
100 $100 – $400
250 $250 – $1,000
500 $500 – $2,000
1,000 $1,000 – $4,000

  • Not all sealant types have the same water resistance.

  • Use a silicone-based or acrylic-elastomeric coating for modified bitumen and EPDM roofs.

  • Recovering a flat roof with PVC, TPO, or EPDM membrane costs $4 to $10 per square foot, depending on the material. A partial or full recover is a good option for a roof with damage on its surface but not its insulation or decking.

Flat roof replacement cost

A flat roof costs $3 to $11 per square foot to replace on average. Consider replacing instead of repairing a flat roof that is 10 to 15 years old and needs extensive repairs.

Flat roof replacement cost
Roof size (square feet) Average cost to replace
800 $2,400 – $8,800
1,000 $3,000 – $11,000
1,500 $4,500 – $16,500
2,000 $6,000 – $22,000
2,500 $7,500 – $27,500
3,000 $9,000 – $33,000
3,500 $10,500 – $38,500

Additional costs to repair a flat roof

The cost to repair a flat roof depends on the roof size, material, job complexity, and damage severity.

Common flat roof repair costs
Factor Average cost
Blistering, cracking, alligatoring repair $250 – $1,250
Sagging / water pooling repair $800 – $2,500
Flashing repair $200 – $500
Rafter repair $300 – $1,700+
Roof decking repair $200 – $2,500
Water damage / structural repair $500 – $3,000
Cleaning $250 – $600
Insulation $1,100 – $9,000
Snow removal $200 – $500
Drip edge installation $150 – $600
Roof vents installation $200 – $700
Painting (metal) $1,450 – $3,250
New gutters $600 to $1,600
Roof inspection $100 – $400
New drain $70 – $340

  • Blistering / cracking – Repairing a blistering, cracking, or alligatoring roofing membrane costs $250 to $1,250 on average. These issues are typically caused by sun exposure, severe weather, and age.

  • Sagging / pooling – Sagging roof repair costs $800 to $2,500 for sections up to 100 square feet. Fixing minor sagging may only require basic rafter ties. Severe cases may require replacing rotted rafters or a full roof replacement.

  • FlashingRoof flashing repair costs $200 to $500 on average for skylights, chimneys, and vents. Completely replacing and resealing all flashing costs $400 to $1,000. Flashing is typically metal and prevents leaks around fixtures.

  • Rafter Rafter repair costs $300 to $1,700+. Rafters should be repaired or replaced if there is water damage or wood rot.

  • Roof decking Roof decking replacement costs $2 to $5 per square foot. Decking, or sheathing, is the plywood layer between trusses and roofing material.

  • Water damage – Roof structure repair costs $500 to $3,000, depending on the severity. Roof structure and water damage may require replacing decking, underlayment, and roof material.

  • CleaningRoof cleaning costs $250 to $600 or $0.15 to $0.70 per square foot on average, depending on the cleaning method.

  • InsulationReplacing roof underlayment costs $1,100 to $9,000 or $0.75 to $4.00 per square foot. Polyiso insulation is used instead of underlayment on rubber roofs and costs $0.50 to $3.00 per square foot with installation.

  • Snow removalRoof snow removal costs $200 to $500 and is recommended after heavy snowfall of 6 inches or more.

  • Drip edgeDrip edge installation costs $150 to $600 or $1.50 to $3.00 per linear foot when reroofing a house. Installing drip edges on an existing roof costs $5 to $9 per linear foot.

  • VentRoof vent installation costs $200 to $700.

  • Painting Metal roof painting costs $1,440 to $3,264 or $1.20 to $2.72 per square foot.

  • Gutters Installing gutters costs $600 to $1,600 or $4 to $8 per linear foot on average.

  • Drain – Repairing or adding a roof drain costs $70 to $340 on average. Proper drainage prevents pooling water and expensive repairs.

Cost to repair a flat roof by material

Flat roof repair cost by material
Material Repair cost per square foot
Built-up roof cost $2 – $7
EPDM rubber membrane roof cost $2 – $10
TPO membrane roof cost $2 – $9
PVC membrane roof cost $3 – $12
Fiberglass (GRP) roof cost $3 – $8
Modified bitumen roof cost $3 – $8
Rolled asphalt roof cost $1 – $6
Spray foam roof cost $2 – $3
Metal roof cost $5 – $10
Concrete roof cost $4 – $15

Labor cost to repair a flat roof

Roofing professionals charge $45 to $75 per hour for labor on average, depending on the scope and type of damage. The following factors affect the cost to repair a flat roof:

Get free estimates from roofing companies near you.
  • Roof type – Some flat roof materials, such as metal or concrete, cost more to repair.

  • Roof size, pitch, and slope – Labor prices are higher for large roofs and pitches higher than 4:12.

  • Size and type of damage – Some repairs take longer to complete, increasing costs.

  • Permits – Roof repair permits cost $75 to $250, depending on the size and location. Contractors typically include permit fees in the estimate.

  • Emergency fees – Many contractors charge $200 to $300 for 24/7 emergency repairs.

Frequently asked questions

How often should a flat roof be replaced?

A flat roof should be replaced after 15 to 25 years. Regular inspections may catch damage before it becomes too expensive. Consider replacing instead of repairing a flat roof that is 10 to 15 years old and needs repairs.

How often should a flat roof be inspected?

A roof inspection costs $100 to $400 on average, depending on the roof size, complexity, and inspection method. Professional inspections are recommended every 3 to 5 years, but you should self-check at least once per year to look for damage.

Why do flat roofs leak?

Flat roofs leak because of cracks or punctures in the membrane, worn flashing or seams, or clogged drains. Drainage problems and small leaks are simple to fix but may cause expensive repairs if ignored.

Are flat roof repairs covered by insurance?

Homeowners insurance may cover flat roof repairs for damage caused by an accident or severe weather but not for normal wear and tear. Check your insurance for coverage details.

Getting estimates from roof repair contractors

Before hiring a roof repair contractor near you, be sure to:

  • Get three or more quotes to compare.

  • Read their reviews on HomeGuide and Google.

  • Look for companies with these qualifications:

  • State contractor license

  • National Roofing Contractors Association (NRCA) certification

  • International Association of Certified Home Inspectors (InterNACHI) certification

  • Select a certified, insured, bonded company with five or more years’ experience.

  • Be careful with extremely low or high price quotes.

  • Beware of companies who recommend a full roof replacement if only repairs are needed.

  • Verify that the roofing contractor has experience with your roof type.

  • Ask for a clear written estimate and warranty before work begins.

  • Avoid large upfront payments. Instead, negotiate a payment schedule and save receipts.

Questions to ask

  • How long have you been repairing flat roofs?

  • Are you licensed, insured, and bonded?

  • Can you provide references for past work?

  • Are you a member of the NRCA or InterNACHI? What certifications do you have?

  • Do you offer any specials or discounts for storm damage?

  • Can you provide a detailed quote?

  • Does your quote include waste disposal or taxes?

  • What extra costs should I expect?

  • How long will the project take?

  • What will you do in the event of unexpected bad weather?

  • How will you access my roof?

  • Will the repairs require a permit, and if so, will you obtain one?

  • What does your warranty include?

  • Do you offer financing?