Choosing the Right Flat Top Roof: A Guide to Materials and Types

Learn expert tips on choosing the perfect flat top-roof for your home or business.
Modern home with a flat top roof.

Flat roofs have become increasingly popular because of their sleek and modern look.

However, with the rise of flat roofs comes the need for more information about choosing the right one for your needs.

This guide provides all the information about flat-top roofing projects, materials, types, and considerations.

From roofing cement to the roof deck, we’ll cover all the key elements of the roofing industry to ensure your new or existing flat roof won’t be a leaking nightmare.

Understanding the Pros and
Cons of Flat Rooftops

Roofer measuring a flat rooftop.

Flat rooftops have pros and cons to consider for roofing options.

Understanding the advantages and disadvantages before choosing a level flat roof replacement option for your home or business can help ensure you make an informed decision.

Here are some key points to consider when weighing the benefits of flat rooftops.


  • Horizontal-plane roofs are typically less expensive to install than other roof types.
  • They offer a sleek and modern aesthetic for your home or business.
  • Flats are easier to access for repairs, maintenance, and insulation.
  • With proper maintenance, they can last up to 40 years.


  • Flats are more prone to leaks because of their low slope design.
  • They require frequent maintenance (sometimes every 2-3 years) to remain watertight.
  • Heat absorption is higher for flat rooftops, which can lead to increased energy costs during the summer months.

Now that you understand the pros and cons, let’s look at the materials and types available.

Types of Materials Used for Flat Roofs

Roofer working with types of materials used for flat roofs.

There are several materials commonly used for flats.

The choice of material depends on factors such as budget, climate, and desired aesthetics.

Here are some of the most popular materials used for level roofs.

▪️ Built-Up Roofing (BUR)

Built-up roof diagram.

Built-up roofing, known as tar, asphalt, and gravel, is one of the oldest and most traditional materials for level roofs.

It comprises multiple layers of felt or fiberglass saturated with asphalt and topped with granules of gravel or minerals.

BUR provides excellent waterproofing and is known for its durability. However, it can be heavy and labor-intensive to install.

▪️ Modified Bitumen

Modified Bitumen Roofing

Modified bitumen is a modern variation of BUR. It is made from asphalt modified with a synthetic material or rubber or plastic polymers to enhance its performance.

Modified bitumen comes in rolls or sheets that are torch-applied, cold-applied, or self-adhered. It offers good flexibility, durability, and UV resistance.

It is also relatively easy to install compared to BUR.

▪️ Single-Ply Membrane

Single-Ply System

Single-ply membranes are popular for their ease of installation and affordability.

There are three main types of single-ply membranes used for flat rooftops.

  • Ethylene Propylene Diene Monomer (EPDM)

EPDM is a synthetic rubber membrane highly durable and resistant to UV radiation, weathering, and punctures. 

You can get large sheets that can be fully adhered, mechanically fastened, or ballasted and cement together with gravel cement.

  • Thermoplastic Olefin (TPO)

TPO is a single-ply adhesive membrane made from polypropylene and ethylene-propylene rubber. 

It offers good resistance to UV radiation and chemicals. Installers heat-welded the adhesive TPO membranes together during installation.

  • Polyvinyl Chloride (PVC)

PVC is a plastic membrane with excellent durability, chemical and fire resistance. 

It is usually installed by heat-welding the seams. PVC membranes are known for their energy efficiency and their reflective coating properties.

Metal Roofing 

Flat metal roof.

Metal roofs, such as standing seam roofs, are becoming increasingly popular for flat roofs. 

They are lightweight, durable, and can be made from metals like steel, aluminum, or copper. 

Metal roofs offer good resistance to fire, wind, and hail damage.

They can be expensive upfront but provide long-term value because of their longevity.

These are just a few examples of the materials used for flat rooftops.

Each material has its advantages and considerations, so it’s essential to consult with a roofing professional to determine the best choice for your specific needs.

10 Factors to Consider for Flat Roof Replacement Options

Roofer working on a flat roof replacement.

When considering a flat roof replacement, you must consider several important factors. 

Here are some key considerations to help you make an informed decision.

1. Roofing Material

Choose the right material based on your budget, climate, and desired longevity.

Consider the pros and cons of each material, such as durability, maintenance requirements, and energy efficiency.

2. Roofing System

Decide on the roofing system that suits your needs. 

This includes built-up roofing (BUR), modified bitumen, single-ply membranes (EPDM, TPO, PVC), or metal roofing. 

Each system has its installation method and unique characteristics.

3. Roof Slope and Drainage

Flat rooftops should not be entirely flat. They should have a slight slope to ensure proper drainage. 

The pitch will depend on local building codes and the materials used. 

Adequate drainage prevents water pooling, which can lead to leaks and structural and water damage elsewhere.

4. Insulation

Consider the insulation requirements for your low-slope roof. 

Proper insulation helps regulate temperature, improve energy efficiency, and prevent condensation. 

Different roofing materials may have specific insulation requirements, so consult a professional to determine the best insulation solution.

5. Denton County Climate

You need a strong roofing material and system to withstand Denton County’s harsh conditions. 

Some materials may be more suitable for specific climates, so consider factors such as UV resistance, thermal expansion, and wind uplift resistance.

6. Long-Term Maintenance

Consider the maintenance requirements of your chosen flat roofing material and system. 

Some materials may require frequent inspections and maintenance to ensure longevity and prevent leaks. 

Regular inspections and prompt repairs are crucial for flat roofs to avoid costly damages.

7. Cost and Budget

Determine your budget for flat roof repair and replacement options.

Different materials and systems have varying prices, so weigh the upfront expenses against the long-term value and durability of the chosen flat roofing option. 

Consider potential energy savings and maintenance and repair costs over the roof’s lifespan.

8. Warranty and Installation

Check the warranty offered by the manufacturer for the material and the warranty provided by the roofing contractor for the installation. 

Ensure both warranties cover the aspects and duration to protect your investment.

9. Building Codes and Permits

Familiarize yourself with the local building codes and permit requirements for flat roof replacement options. 

Compliance with these regulations is essential to avoid legal issues and ensure you protect the safety and integrity of the new roof itself.

10. Professional Roofing Contractor

Engage a reputable, experienced roofing contractor to install your flat roof repair kit or replacement. 

Proper installation is crucial for the performance and longevity of the roof.

Research and get multiple quotes, check references, and verify licenses and insurance before making a final decision.

How to Know When You Need Flat Top Roof Repair

Flat Roof Replacement Vs. Repair: Making the Right Decision

Your commercial or residential building’s flat top roof is an important structure that protects you and your belongings from outside elements. 

However, like every other building component, they will wear out over time.

A flat-top roof problem can result in major inconvenience, damage, and even hazards. 

Therefore, regular inspection and repair of your flat top roof is an essential maintenance practice that should be done with care.

▪️ Watch out for Cracks

Flat top roof repair cracks.

Cracks and punctures in your roof membrane can indicate your flat top roof needs significant repair. 

These cracks may permit water to penetrate the roof structure, damaging your building’s interior and possibly contributing to mildew and mold growth.

▪️ Look for Ponding Water

Common Flat Roof Issues and Their Causes

Another issue is ponding water which means your flat-top roof is not draining water as it should.

Prolonged ponding can also contribute to algae growth and cause your roof to age prematurely.

▪️ Check for Blisters

Check for Blisters.

Blisters happen when air or moisture gets trapped beneath your flat roof membrane, resulting in bubbles within the rooftop. 

This problem makes your flat top roof look unsightly and can develop into further problems like leakage and collapse of the roofing system if left unattended. 

Blisters also jeopardize space optimization since the roofing structure can collapse anytime.

▪️ Consider Your Roof’s Age

Consider Your Roof's Age.

An aging flat-top roof is likely to require repair or replacement in the near future. 

As the roof continues to deteriorate, it is vulnerable to environmental factors like strong winds and heavy rain, leading to damage. 

Materials in terminated flat-top roofs disintegrate over time, causing them to become more vulnerable to leaks and other significant repairs.

▪️ Inspect Your Roof’s Flashing

Inspect Your Roof's Flashing.

Flashing is the protection between two points in your roof structure, such as walls and chimneys.

These points are vulnerable to roof leaks and other forms of rooftop damage.

If you notice the flashing on your roof is damaged or degraded, there is a high likelihood of more significant issues happening in the future.

8 Expert Tips for Choosing the
Best Flat Rooftop Materials

Type of flat rooftop materials being laid on flat roof.

Choosing the best materials requires careful consideration of various factors.

Here are some expert tips to help you make an informed decision.

1. Evaluate Durability

Low-inclined roofs are more prone to leaks than sloped roofs, so durability is crucial.

Look for longevity and weather-resistance materials like EPDM, TPO, PVC, or metal roofing.

Consider the material’s ability to withstand UV radiation, temperature fluctuations, and potential debris or foot traffic damage.

2. Assess Waterproofing Properties

Proper waterproofing is essential since horizontal roofs lack natural water runoff.

Ensure that the materials you choose have excellent waterproofing capabilities.

Look for options with multiple layers, strong seams, and effective methods of preventing water penetration, such as built-up roofing or even single-layer two-ply membranes.

3. Consider Insulation

Adequate insulation helps regulate the temperature inside your building and can lead to energy savings.

Choose materials with good insulation properties, or consider adding insulation layers.

Again, consult professionals to determine the best insulation options for your needs.

4. Evaluate Maintenance Requirements

Different materials have varying maintenance needs.

Consider the time, effort, and cost required for routine maintenance.

Some materials may require more frequent inspections, cleaning, or resealing.

Assess whether you have the resources and willingness to provide the necessary care to ensure the longevity and performance of the most damaged roof material.

5. Reflectivity and Energy Efficiency

Flat rooftops absorb more heat than sloped roofs, increasing cooling costs.

Look for high reflectivity or thermal emissivity materials, which can reduce heat absorption and lower energy consumption.

Single-ply membranes and cool roof coatings can offer excellent reflectivity and energy efficiency.

6. Research Local Building Codes and Regulations

Familiarize yourself with the local building codes and regulations on level roof materials.

For example, some areas may have specific requirements for fire resistance, wind uplift resistance, or environmental considerations.

Ensure the materials you choose meet or exceed these standards.

7. Consider Aesthetics

While functionality and performance are paramount, aesthetics also play a role in choosing materials.

First, consider the overall look and style you want to achieve.

Some materials, like metal roofing, can provide a modern and sleek appearance, while others, like built-up roofing with gravel, offer a more traditional look.

8. Seek Professional Advice

When choosing materials, consulting with roofing professionals is crucial.

They can assess your needs, provide recommendations based on local climate and building requirements, and offer insights into the pros and cons of different materials.

Professionals can also ensure proper installation, which is critical to the performance and longevity of the roof.

Selecting the best materials involves balancing durability, waterproofing, insulation, energy efficiency, maintenance requirements, and aesthetics.

By considering these factors and seeking expert advice, you can make an informed decision that meets your needs and provides a reliable, long-lasting flat rooftop solution.

1. How long do flat roofs last?

The lifespan of a level of roofing cement used can vary depending on the materials used and the level of maintenance.

On average, a well-installed and well-maintained flat roof can last 15 to 30 years, but some materials like EPDM or PVC can last up to 40 years or more.

2. What are the disadvantages of flat roofs?

Some disadvantages of flat roofs include a higher risk of leaks because of their low slope, regular maintenance to ensure their waterproofing, and higher energy costs during hot weather due to heat absorption.

Flat roofs can also require more frequent replacement of certain materials than sloped roofs.

3. Is a flat roof cheaper than shingles?

Flat roofs are more cost-effective compared to sloped roofs with shingles. Flat roofs require less material and less labor costs for installation.

However, the overall cost can vary depending on the chosen materials, the complexity of the entire roof and design, and other factors.

4. What does it cost to replace a flat roof?

The cost of replacing a flat roof depends on various factors, including the size, the chosen materials, the complexity of the installation, and the region where you live.

Obtaining quotes from professional roofing contractors is recommended to get accurate cost estimates based on your specific requirements.

5. What is a flat roofer?

A flat roofer is a professional roofing contractor or specialist specializing in installing, repairing, and maintaining flat roofs.

6. What is the life expectancy of a flat roof?

The life expectancy of a flat roof can vary depending on factors such as the materials used, climate conditions, maintenance, and quality of installation.

On average, a horizontal roof can last 15 to 30 years, but some materials have longer lifespans, reaching up to 40 years or more.

7. Is a flat roof more expensive than a regular roof?

A flat roof costs less than a regular sloped roof, as installation requires less material and labor. 

However, the price of a pitched roof can vary based on the chosen materials and other factors.

8. What materials replace a flat roof?

Several materials are used to replace or install flat roofs, including built-up roofing (BUR), modified bitumen, single-ply membranes (EPDM, TPO, PVC), and metal roofing.

9. What is the best material for a flat roof?

The best material for a flat roof depends on various factors, such as budget, climate, and desired characteristics.

Some popular options include EPDM for its durability, TPO for its energy efficiency, PVC for its longevity, and metal roofing for its durability and modern aesthetics.

10. What kind of roof can you put on a flat roof?

Various materials and systems can be used on a flat-top roofing project, including built-up roofing, modified bitumen roofs, single-ply membranes (EPDM, TPO, PVC), or metal roofing.

11. What is a PVC flat roof?

A PVC flat roof is a roofing system that uses a single-ply membrane roof made of polyvinyl chloride (PVC) material. PVC roofs are known for their durability, resistance to chemicals and fire, and energy efficiency.

12. What are the options for fixing a flat roof?

The options to fix a flat roof may be depending on the issue. They can include patching leaks, repairing damaged areas, re-coating reflective coating of the whole roof surface, reinforcing seams, or replacing damaged sections of a built-up roof.

In some cases, it may be necessary to replace the leaking flat roof completely if the damage is extensive or it has reached the end of its lifespan.

Consulting with a professional roofer is recommended to assess the specific issue and determine the repair options.

13. Is it possible to repair a flat roof?

We can repair most flat roofs depending on the extent and nature of the damage. Minor issues, such as sun damage, small cracks, leaks, or damaged sections, can often be repaired by patching or sealing the affected area.

However, addressing repairs as soon as possible is crucial to prevent further roof damage and avoid damaged areas needing more extensive repairs or replacing the entire roof.

14. What is the best roofing system for a flat roof?

The best roofing system for a flat roof depends on various factors such as budget, climate, desired lifespan, and specific requirements.

Popular options include built-up roofing (BUR) for its durability, modified bitumen for its versatility, and single-ply membranes like EPDM, TPO, or PVC for their longevity and performance.

Consulting with a roofing professional can help determine the best system for your needs.

15. How do you fix flat roof leaks?

Fixing flat roof leaks involves identifying the source of the leak and applying appropriate repair techniques. This repair may include patching the damaged area, reinforcing seams, or using specialized sealants or coatings.

It’s crucial to address leaks promptly and thoroughly to prevent further damage to the roof structure and interior of the building. 

We recommend consulting with a professional roofer for proper leak diagnosis and repair.

16. How long does PVC flat roof last?

A PVC flat roof, when properly installed and maintained, can have a lifespan of 20 to 30 years or more. PVC roofs are known for their durability, UV radiation, chemical resistance, and longevity. 

Regular inspections and maintenance can maximize the lifespan of a PVC flat roof.

Flat Roof: A Modern Solution
with Considerations

A white building with a flat roof with rolled roofing.

Flat roofs offer a sleek and modern aesthetic for homes and businesses.

However, choosing the right materials and considering essential factors is crucial for successfully installing built-up roofs.

Understanding the pros and cons and evaluating durability, waterproofing properties, insulation, and maintenance requirements is critical in selecting the best flat roof materials.

Don’t hesitate to contact DKG Roofing at (940) 497-2833 for a consultation. Invest in a well-designed and properly maintained flat roof that will provide lasting protection and enhance the aesthetics of your property.

About DKG Roofing

With over two decades of serving homeowners in North Texas and Denton Roofing, DKG Roofing has established itself as a highly sought-after roof repair and replacement contractor.

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