Residential Roofing

How Long Does It Take to Replace a Flat Roof?

When it comes to protecting your home, a well-maintained flat roof is essential. As a homeowner, it's crucial to know how long it takes to replace a flat roof, as this helps you plan accordingly and ensures minimal disruption to your daily life. In this comprehensive guide, we'll explore the factors that affect the duration of flat roof replacement, the steps involved in the process, and provide answers to common questions related to flat roofs.

On average, it takes 2 to 3 days to replace a flat roof, depending on various factors such as roof size, material, and weather conditions.

Factors Influencing Flat Roof Replacement Time

  1. Roof size and complexity: Larger and more complex roofs require more time for replacement. Multiple penetrations, such as skylights or vents, can also add to the project's duration.
  2. Type of roofing material: Different materials may require different installation techniques, which can affect the time it takes to complete the project.
  3. Weather conditions: Adverse weather, such as rain or extreme heat, can cause delays in the roofing process.
  4. Contractor experience and crew size: Experienced contractors with sufficient crew members can complete the job more efficiently and quickly.

Common Flat Roofing Materials and Their Replacement Time

  • EPDM rubber: This durable synthetic rubber material can be installed relatively quickly, usually taking 1 to 2 days.
  • TPO: Thermoplastic Olefin (TPO) is a popular choice due to its energy efficiency, and it typically takes 2 to 3 days to install.
  • Modified bitumen: This multi-layered material can take slightly longer to install, with a typical timeframe of 3 to 4 days.
  • Built-up roofing (BUR): BUR systems consist of multiple layers and take longer to install, usually around 4 to 5 days.

Steps Involved in Flat Roof Replacement

  • Inspection and assessment: A professional roofer, like the experts at Defense Home & Roofing, will first inspect your flat roof to determine the extent of the damage and the necessary repairs or replacement.
  • Removal of old roofing material: The existing roof material is removed, and any debris is cleared away.
  • Repair or replacement of damaged decking and insulation: Any damaged sections of the roof decking or insulation are repaired or replaced.
  • Installation of new roofing material: The chosen material is installed according to the manufacturer's guidelines and best practices.
  • Final inspection and cleanup: The contractor conducts a final inspection to ensure the work is complete and satisfactory. The site is then cleaned, and any remaining debris is removed.


The time it takes to replace a flat roof varies based on factors such as roof size, material, and weather conditions. By hiring a professional roofing contractor like Defense Home & Roofing, you can ensure that your project is completed efficiently and with minimal disruption to your daily life. Remember that proper maintenance can also help extend the lifespan of your roof, so make sure to inspect and maintain your roof regularly.

FAQ Section

What is the average cost of replacing a flat roof?

The cost of replacing a flat roof depends on the size, material, and labor involved. On average, homeowners can expect to spend between $5 and $10 per square foot.

Can I install a new flat roof over the old one?

In some cases, it is possible to install a new flat roof over an existing one. However, this decision should be made on a case-by-case basis after a thorough inspection by a professional roofing contractor. Installing a new roof over an old one may not address underlying issues and could lead to further problems down the line.

How often should a flat roof be replaced?

The lifespan of a flat roof depends on the materials used and how well it is maintained. Generally, a flat roof should last between 10 and 30 years. Regular inspections and maintenance can help extend the life of your roof. Be sure to check out our guide on how often you should replace your roof for more information.

How can I maintain my flat roof to prolong its lifespan?

  • Regular maintenance is crucial to extending the lifespan of your flat roof. Some steps to maintain your flat roof include:
  • Inspecting the roof for damage, pooling water, or debris at least twice a year.
  • Removing any debris, such as leaves or branches, to prevent water buildup.
  • Checking for and repairing any cracks, tears, or blisters in the roofing material.
  • Modified bitumen: This multi-layered material can take slightly longer to install, with a typical timeframe of 3 to 4 days.
  • Ensuring that drains and gutters are clear and functioning properly.\
  • Hiring a professional roofing contractor, like Defense Home & Roofing, for regular inspections and maintenance.

What are the signs that my flat roof needs to be replaced?

Some common signs that your flat roof may need replacement include:

  • Persistent leaks, even after repairs have been made.
  • Extensive damage to the roofing material, such as large cracks or blisters.
  • Sagging or uneven areas on the roof surface.
  • Mold or water damage inside your home, indicating potential roof leaks.
  • The roof is approaching or has exceeded its expected lifespan.

If you notice any of these signs, it's essential to consult with a professional roofing contractor, To assess the situation and determine the best course of action.

thank you from your Defense team