Everything You Need to Know about When to Replace a Flat Roof

By Applied Roofing Services

Oct 26, 2022

Flat Roof

Everything You Need to Know about When to Replace a Flat Roof

A flat roof, after installation, can last for a very long time, but you will need to closely monitor the condition of your commercial roof to identify any wear and tear. Frequent inspections and proper maintenance could significantly extend the lifespan of your flat roof. However, it may still need replacement at some point. Continue reading to learn more about when it's time to replace your flat roof and how to do it.

How Often Does a Flat Roof Need to Be Replaced?

If properly installed, flat roofs can last 15 to 20 years. The lifespan of your flat roofing system is determined by various factors, including the material used to construct it, the materials used to cover it, and how well the roof is maintained.

Check the following to determine the health of your flat roof:

  1. Check for any visible damages to your flat roof. Minor damages can be repaired with minimal maintenance. Other serious damages could require you to replace your flat roof completely.
  2. Check to see if your roof leaks. In the event of a leak, it is best to have your roofing system inspected to determine whether it requires repairs or replacement.
  3. Since one of the main advantages of flat roofs is their capacity to provide insulation and save energy, if your flat roofing system does not help you reduce your energy costs, it is likely time to replace it.
  4. Finally, if your roof has reached the end of its lifespan, even if there are no visible damages, it is time to consider a full replacement.

The Cost of Flat Roof Replacement

Flat roofs do not offer much protection against the buildup of dirt and debris, and the lack of a slope may cause water blockages if proper drainage systems are not present. Therefore, it is likely that a flat roof will not last as long as a sloped roof. At times it may start performing poorly in just a decade.

For smaller membrane flat roof replacements, the price per square foot ranges from $14 to $17. For slightly larger projects, it is closer to $12. The cost of replacing a screw-down panel metal flat roof starts at around an affordable $4.50 per square foot. A 24 gauge steel standing seam metal roof should cost between $12 and $15 per square foot for a flat roof without any penetrations.

The removal and disposal of old roofing materials, adding more layers of underlayment, ventilation, and roof drains are additional factors that will affect the overall cost of replacing a flat roof.

How to Improve Installation of Flat Roofs?

Having a professional contractor install your roof is one way to increase the quality of the job, as self-installation could lead to a roof that is installed incorrectly. To fully assess the contractor's qualifications, you must research their level of knowledge and expertise.

See Also: 5 Flat Roofing Options for Commercial & Industrial Buildings

The Best Materials for Flat Roofing

1. PVC Roofing

Also known as polyvinyl chloride, it offers excellent durability with a lifespan of 20 to 30 years. It is highly resistant to impact and cracking.

2. TPO Membrane Roofing:

TPO membrane is a good commercial roofing option as it provides outstanding durability with a lifespan of 25 years. It can also reflect heat which helps to keep the rooms cooler.

3. Metal Roofing:

This offers the best durability, with the longest roofing lifespan of 25 to 35 years. Metal roofing is also highly reflective, increasing energy efficiency.

4. Modified Bitumen Roofing:

It is considered the most cost-effective option. This roofing type is similar to EPDM but is made from asphalt instead of recycled rubber. It is more susceptible to cracking and blistering, with an average lifespan of 10 to 15 years.

Pros & Cons of Flat Roofing


  • Inexpensive: Flat roofs are cheaper than most roofing systems as both the materials and the labor cost less in their installation.
  • More Outdoor Space: You can utilize your outdoor area by installing solar panels or can use it as a dining space on your flat roof.
  • Easier to Maintain: It is easier and safer to go up the flat roof and get repairs done than sloped roofs which present more risk of falling off.
  • Modern Look: Flat roofs make your home look modern and sleek. 


  • Minimum Insulation: Sloped roofs provide more insulation due to the existence of extra space in the form of attics. However, with no attics, flat roofs provide less insulation.
  • Susceptible to Leaks: Flat roofs have poor drainage as there are no slopes. Since water tends to pool on flat roofs, they are subsequently more susceptible to leaks.
  • Less Indoor Space: Flat roofs don’t have attics, which can eliminate extra room for storage from your home. However, flat roofs can serve as patios, so it isn’t a complete loss of space.

See Also: Best Flat Roof Benefits in Orange County

Maintaining a Flat Roof

Here are some suggestions to maintain your roof and significantly increase its lifespan: 

1. Regular Inspection & Maintenance

Regular inspections are essential because they help you to identify issues with your roof that are not immediately apparent. It will be easier to properly maintain your commercial flat roof as a result of these regular inspections, which provide you with an estimate of all issues.

2. Frequently Remove the Dirt and Debris

The accumulation of dirt and debris may cause cracking or other drainage issues. In order to prevent leaks and cracks, it is best to regularly sweep off any dirt or debris from your flat roof.

3. Gutter & Drain Maintenance

Water frequently collects on flat roofs. Your flat roof might develop cracks and leaks as a result of pooling water. The best course of action is to check your drainage outlets for blockages and sweep away any standing water on the roof.

4. Recoating Your Roof Often

Recoating your flat roof every two to four years could significantly increase its durability. In doing so, you might also need less maintenance in the long run.

Applied Roofing Services Can Help You with Your Roof Replacement! 

Are you planning to replace your commercial flat roof? If yes, then you have come to the right place. At Applied Roofing Services, we provide complete roof replacement at a reasonable price. Our professional commercial roofing contractors in Orange County, CA, are fully licensed and insured. Contact us today or call us at 714-632-8418 to get a free quote.

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