Are Flat Roofs More Expensive? An In-Depth Cost Analysis

cost of a flat roof

When choosing a roof, there are a ton of options and considerations. One of the things critical to most people is the price of a new roof and the recurring cost of maintenance associated with their choice.

Generally, flat roofs are less expensive to install than pitched roofs. However, most flat roofs have shorter lifespans than roofs with a slope, so a pitched roof is likely more affordable in the long run. Flat roofs also have less efficient drainage, leading to more maintenance and repair costs.

In a broad sense, you have two options regarding roof design: flat or pitched. Both have their respective benefits and disadvantages. There’s no “right” answer, but the more information you have, the better equipped you are to make the best choice for your situation.

Let’s take a closer look at the pitched and flat roofs to determine their costs, characteristics, benefits, and disadvantages.

Are Flat Roofs More Expensive Than Pitched Roofs?

There are many variables to consider when determining which type of roof is more expensive than the other. The price of materials, installation, maintenance, repairs fluctuates depending on location and time of year.

And that’s not even mentioning the varying lifespans of the different material options for flat and pitched roofs. All of that to say, there are many variables and nuances to this question that are important to consider.

Materials Costs
A significant expense when installing a roof is the cost of materials. Luckily, there are many material options for all roof designs to meet nearly any budget.

It is important to note that the roofing material prices often reflect their durability. It is not always the case, but more affordable roofing materials can end up costing more in the long run because they require more frequent repairs and maintenance, not to mention that they usually have shorter lifespans.

As an aside, most roofers often give the price of a roofing project in squares (1 square is equal to a 10x10 area, or 100 square feet).

Here are three of the most popular types of flat roof materials and their associated prices:

Flat Roof MaterialsCost Per Square FootPrice Per Square
(100 sq ft.)
Estimated Lifespan
Built-Up Roof (BUR)$6-$8$600-$80020-30
Single-Ply Membrane$4-$7$400-$70015-30
Modified Bitumen$2.50-$5$250-$50010-25

There are more options when it comes to materials for pitched roofs, but here are four of the most popular and their associated prices:

Pitched Roof MaterialsCost Per Square FootPrice Per Square
(100 sq ft.)
Estimated Lifespan
Asphalt Shingles$1.50-$4$150-$40015-20
Concrete Tiles$2-$5$200-$50030-50
Clay Tiles$7-$15$700-$1,50050-100

Installation Costs
Many people fixate on the roofing material price, but installation costs are often much more influential to the bottom line. On a typical roofing project, installation and labor expenses can account for up to 60% of the total cost of the roof.

As a general rule, expect to pay an additional $1-$3 per square foot to have a roofing company install a flat roof professionally. Installation costs are typically higher for a pitched roof at around $2.50-$5 per square foot.

Many factors influence roof installation costs, but here are a few of the main reasons:

  • Roof Accessibility: Having an accessible roof will make installation easier, quicker, and less expensive. Large trees, bushes, or uneven ground around the side of the home can make things more difficult.
  • Roof Slope: Generally speaking, the lower the roof slope, the easier it is to install and work. Moving around on a flat roof is easier than a highly pitched roof with many ridges and valleys.
  • Specialized Knowledge: Some roofing materials, such as metal or rubber membrane roofing, require specialized knowledge and skills to install. It’s worth getting it done right the first time by hiring an experienced company, but it usually costs more.

Maintenance and Repairs Costs
The cost of roof maintenance and repairs largely depends on the extent of the damage, but most roofers will charge $40-$120 per hour. The national average cost for roof repairs is approximately $75 per hour.

Generally, flat roofs will require more maintenance and repairs than pitched roofs. Here are a few significant reasons why flat roofs typically require more repairs and maintenance:

  • Drainage issues
  • Leaking seams
  • Debris punctures

As you might expect, flat roofs generally do not drain off water as well as pitched roofs. This lack of efficient drainage can cause water or debris to build up, leading to more severe issues that are not nearly as prevalent on pitched roofs.

The rubber membrane used on most flat roofs comes in large rolls or sheets that must overlap on the roof to create a cohesive surface. While an experienced roofer will ensure these seams are water-tight, they are a prime location for leaks to develop over time.

Debris damage is one of the more common reasons for repairs and is likely to occur on flat and pitched roofs. Using a small patch on a rubber membrane flat roof is much easier and cheaper than repairing most pitched roof material options.

Final Thoughts

With all of the above data and analysis in mind, flat roofs tend to be less expensive than pitched roofs based purely on material and installation costs. However, most flat roof materials have a lower expected lifespan than popular materials used on pitched roofs.

So looking at the cost per year of each type of roof, the pitched roof comes out to be significantly more affordable over the long run.

In the end, there are so many variables in these calculations that saying definitively that flat roofs are less expensive than pitched roofs is impossible. The exact prices in your area, the climate, and how well you maintain your roof plays a vital role in which type of roof is more or less expensive in your situation.

ItemFlat RoofPitched Roof
Roof Size (sq ft.)2,0002,000
Typical Material Price
(per sq ft.)
Typical Installation Price
(per sq ft.)
Average Lifespan (years)1530
Total Price$10,000$16,000
Price Per Year$667$533

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