What is the average cost of flat roof replacement? Should I DIY or hire a professional to replace my flat roof?
Deep Hill Blog
If you need to replace your flat roof, you might find it’s not as costly as other types of roofing, but it can still be quite expensive. Typically, replacing a flat roof can range from $3,000 to $20,000, depending on factors like its size, the materials used, and its specific type.
On average, homeowners tend to spend around $9,000 for this replacement. The cost varies based on factors such as the materials used, the size of the roof, and its specific type.
This guide can help you understand these costs better so you can plan your budget accordingly for this significant home improvement project.
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What is the average cost of flat roof replacement?
Flat roof replacement costs vary depending on factors such as size, materials, and specific needs of the project. On average, homeowners can expect to spend around $9,000 for a flat roof replacement, with costs ranging from $3,000 to $20,000. Understanding the breakdown of costs based on roof size can provide a clearer picture for budgeting purposes.
Roof replacements are typically priced per square foot, meaning larger roofs will incur higher costs. The cost per square foot varies depending on the materials chosen for the replacement. For instance, materials can range from $3 to $14 per square foot.
Here’s a breakdown of the average costs based on roof size:
- For a 500 square foot roof, homeowners can expect to pay between $1,500 and $7,000 for replacement.
- For a 1,000 square foot roof, costs may range from $3,000 to $14,000.
- A 1,500 square foot roof replacement could cost between $4,500 and $21,000.
- Larger roofs, such as a 2,000 square foot area, may incur costs ranging from $6,000 to $28,000.
- The largest roofs, spanning 2,500 square feet, may have replacement costs between $7,500 and $35,000.
Factors such as the complexity of the project, accessibility of the roof, and any additional features or requirements can also impact the overall cost. It’s important for homeowners to consider these factors and obtain quotes from multiple contractors to ensure they are getting a fair price for their flat roof replacement.
Ultimately, investing in a flat roof replacement is a significant home improvement project that can enhance the durability and longevity of the property. By understanding the average costs associated with different roof sizes, homeowners can better plan and budget for this essential maintenance task.
Cost of a flat roof by material
Different materials are used for flat roofs, each with its own cost 
and characteristics. Here’s an overview of various flat roofing materials and their associated costs:
Metal: Typically the priciest option, metal roofs range from $4 to $30 per square foot. However, they offer excellent durability and can withstand harsh weather conditions like hail and strong winds.
Rubber Membrane (EPDM): With a lifespan of about 50 years, EPDM rubber roofing costs between $4 and $13 per square foot. It’s known for its durability and ability to endure extreme weather.
Thermoplastic Polyolefin (TPO): Lightweight and low maintenance, TPO roofing is often used for commercial buildings. It ranges from $3 to $14 per square foot and is highly durable and water-resistant.
Built-Up Roofing (BUR): Comprising layers of bitumen and reinforcing fabrics, BUR roofing costs between $4 and $10 per square foot. It offers protection against water, sun, and physical damage.
Glass-Reinforced Polyester (GRP): GRP, a type of fiberglass, is versatile and affordable, priced between $4 and $6 per square foot. It’s durable and corrosion-resistant, suitable for industrial and aesthetic applications.
Modified Bitumen: Costing between $4 and $8 per square foot, modified bitumen enhances asphalt roofing with improved flexibility and durability.
Polyvinyl Chloride (PVC): PVC roofing membranes are impact-, water-, and fire-resistant. Typically ranging from $4 to $7 per square foot, they are often light-coloured to reflect sunlight and reduce cooling costs.
Concrete: Concrete roofs, available as tiles or poured concrete, are exceptionally strong and fire-resistant, priced between $4 and $8 per square foot.
Polyurethane: Applied as a liquid mixture that expands into a rigid foam, polyurethane roofing costs between $4 and $7 per square foot. It offers excellent water resistance, durability, and insulation properties.
Understanding the cost and characteristics of each material can help homeowners make informed decisions when selecting the right flat roofing option for their needs and budget.
What are the factors that affect flat roof replacement costs?
When considering the cost of replacing a flat roof, various factors come into play, influencing the final expenses. Understanding these factors can help homeowners plan their budgets more effectively.
One crucial factor is the type of flat roof being replaced. Different roof types serve distinct purposes and come with varying costs:
- Cold roofs: These roofs have insulation below the roof deck, providing ventilation above the insulation. Average costs range from $3 to $9 per square foot.
- Warm roofs: With insulation placed on top of the roof deck, maintaining consistent temperatures, warm roofs typically cost between $6 and $11 per square foot.
- Inverted roofs: Featuring insulation above a waterproof layer like a liquid membrane, inverted roofs protect against extreme weather. Replacement costs average between $4 and $9 per square foot.
- Hybrid roofs: Combining elements of both cold and warm roofs, hybrid roofs utilize insulation above and below the roof deck, with costs ranging from $4 to $11 per square foot.
- Curved roofs: Characterized by an arched surface aiding drainage and adding aesthetic appeal, curved roofs incur higher replacement costs, averaging between $8 and $15 per square foot.
- Tapered roofs: These roofs have a slight slope and varied insulation thicknesses, promoting water drainage to prevent pooling. Replacement costs typically range from $7 to $10 per square foot.
- Green roofs: Covered with vegetation to enhance drainage and ecological benefits, green roofs can be among the costliest options, with replacement costs ranging from $10 to $35 per square foot.
Different application methods are used for installing flat roofs, each with its own labour costs:
- Fastened attachment method: Typically costs between $2 and $3 per square foot for labour.
- Ballasted method: Generally incurs labour costs of about $1.50 to $2 per square foot.
- Fully adhered method: Usually involves labour costs ranging from $2.75 to $3.50 per square foot.
Location can also influence replacement costs, with areas having a higher cost of living or experiencing extreme weather often resulting in higher expenses. Labour costs for professional roof replacement typically range from $3 to $7 per square foot, depending on the complexity of the job.
Roof removal is another factor to consider, with costs averaging between $1 and $5 per square foot. If permits are required for the replacement, they can range from $100 to $500, potentially higher for larger roofs. It’s advisable to confirm permit requirements with local authorities.
Proper ventilation and drainage are crucial for flat roofs to prevent moisture buildup and water damage. Adding drains or gutters may cost between $600 and $1,000, while installing a roof vent typically ranges from $300 to $650.
Sealants play a vital role in waterproofing and enhancing roof durability, with prices varying widely from $500 to $2,500 depending on the type and application method.
Considering these factors can help homeowners plan their budget effectively for flat roof replacement projects, ensuring they allocate funds for all necessary components and labour. Consulting with roofing professionals can provide further guidance on specific requirements and costs tailored to individual circumstances.
Should I DIY or hire a professional to replace my flat roof?
Choosing between DIY and hiring a professional for flat roof replacement requires careful consideration. While DIY projects may seem tempting, it’s important to recognize the risks involved. Roof replacement demands specialized skills and knowledge, and improper installation can lead to dangerous and costly issues. Hiring a qualified roofer ensures the job is done correctly, sparing you potential headaches and ensuring the safety of your home.
Flat roofs offer several advantages, but it’s essential to weigh them against potential drawbacks:
Pros:
- Additional space for rooftop gardens, outdoor living areas, and HVAC systems.
- Generally more affordable than other roof types.
- Relatively easy to access, install, and maintain.
- Suitable for solar panel installations.
Cons:
- Potential water drainage issues due to the flat surface.
- Often have shorter lifespans compared to other roof types.
- Less suitable for regions with heavy rainfall or snowfall.
To determine the average costs mentioned in this article, information was gathered from eight providers and cost databases on national and local levels. The averaged figures were accurate at the time of publication but may be subject to change over time.
