Whether constructing a new property or renovating an existing building, one of the most important components to consider is your roof design. Not just the materials you use—though they matter a great deal—but also the roofing style you prefer. Both flat and pitched roofing can offer a variety of benefits, from cost-effectiveness to weather resistance to aesthetics. And the best way to choose which roof is right for your property is by taking a comprehensive look at all of these pros and cons. 

If this feels overwhelming or confusing, you’re in luck—WestBank Roofing is here to help. With over 50 years of experience in the roofing industry, we can share our professional understanding of both types of roofing, as well as install whichever style you choose. 

What Is a Flat Roof?

Flat roofs—or more accurately, low-slope roofs—are mostly level roofing systems with a slight pitch that allows water to drain more easily. Because this slope is often only ¼ to ½ inch per foot, it can allow snow and water to collect over time. As such, these roofs typically use different materials than pitched roofs in order to remain as watertight as possible. Three of the most common flat roofing systems are:

1. Built-up roofs (BURs)

This traditional form of flat roofing consists of layers of material, including insulation board, asphalt and roofing felt. For the finishing touch, a layer of gravel is applied to weigh down and improve the lifespan of the roofing components. Alternatively, a light-colored, reflective cap sheet can be applied in order to boost your roof’s ability to reflect sunlight and release trapped heat.

The assembly method of BURs makes them seamless, durable and long-lasting, and a top layer of gravel can help your roof better withstand damage from foot traffic. But installing BURs is often a time-intensive process, and their weight may make it necessary to add further structural support to your roof. Additionally, while any leaks can be easily repaired, finding the leak may be a rather involved process. 

2. Modified bitumen roof (MBR)

Modified bitumen roofing systems, developed in the 1960s as an improvement on BURs, typically consist of asphalt and materials such as rubber or plastic. This mixture is then reinforced with polyester and/or fiberglass mats, ensuring that the final product is both durable and flexible. Additionally, MBRs are typically more lightweight and easier to install than BURs, and may offer better resistance to heat and cold. 

MBRs may be installed through methods including “torch down,” where an open flame is used to heat the membrane. This seals the seams together and allows the material to adhere to the roofing substrate. Contractors can also utilize self-adhesive roofing, which simply sticks to the material underneath it. 

3. Synthetic rubber single-ply membranes (EPDM)

Ethylene propylene diene monomer, a synthetic rubber material, is one of the most common forms of single-ply flat-roofing membranes. The roofing material is rather simple, consisting of a layer of insulation board topped with the membrane. However, don’t let it fool you; EPDM roofing is able to withstand extreme temperatures and weather conditions, as well as prevent leaks as long as it remains undamaged. 

When installed properly, EPDM roofing may last around 20 years, if not a few decades more. Of course, all of these benefits come with a cost—quite literally, as EPDM roofing may be more expensive than both BURs and MBRs. This material can also be difficult to install if you have roof penetrations such as chimneys and skylights. 

What Is a Pitched Roof?

Pitched roofs are structures with a peak or sloping surface of at least 10 degrees, though many pitched roofs are even steeper. This—alongside the roofing materials you choose—allows water and snow to more easily drain from your roof, lowering the chances of water intrusion. Roof pitch is typically displayed as a ratio; that is, every inch or foot the roof rises in height against every 12 inches or feet it stretches in length. The pitch of your roof determines factors including how walkable it is and what materials are best suited for your property. 

Pitched roofs come in a variety of forms, including: 

1. Mansard

Also known as a French roof, Mansard roofs have double slopes on each side. That is, an upper and a lower slope which meet at a center line. Because the upper slope is much less slanted than the lower slope, this style is considered a low-pitched roof. The shape of these roofs can provide additional room in your interior space, but may be less than ideal for snow- and rain-prone climates.

2. Hip

This roof consists of sloped surfaces on all four sides of your property, all of which are the same length. Their design often provides a boost in stability when compared to gable roofs, and the steep inward slopes make them ideal for wind-, rain- and snow-prone areas. 

3. Gable

Two equally steep panels sit atop your property’s gable ends, or the triangular portions of your exterior walls which sit below the sloped panels. These roofs may provide more interior space for attics or high ceilings, and are generally less labor-intensive to build and fix. Additionally, their steep slope allows them to easily shed water and snow. 

What to Consider When Choosing a Roof Style

1. Costs

When compared to pitched roofs, flat roofing is typically more cost-effective for property owners. Not only are they quicker to install, but they also use fewer materials, lowering the cost of construction. Additionally, the empty space on top of your property can be used for solar panels, allowing you to generate electricity and reduce your utility costs. However, flat roofs may require more maintenance than pitched roofs, and often have less insulation and shorter lifespans. These factors may actually serve to raise costs, negating some of the savings you gain.

2. Climate

While flat roofs may perform better in windy areas, pitched roofs are the better choice for snow- and rain-prone climates. Consider your area’s weather patterns and the materials you plan to use, and talk with your contractor to determine the best choices for your building. 

3.Aesthetics

Flat roofs, with their clean lines and ability to increase indoor space, are ideal for commercial buildings and modern residences. Here, their lack of material options is a benefit rather than a downside; gravel, asphalt and cool roofing are well-suited to a property bathed in neutral tones. Pitched roofs, on the other hand, are the better choice for more traditional buildings, as their shape—as well as material options such as wood, clay and stone—allow them to fit right into classic architectural styles.

4. Usable space

Flat roofs provide more usable space than pitched roofs, allowing you to easily install additions such as solar panels, green roofing or even an outdoor living space. It all depends on your budget, preferences and the structural support underneath. 

Contact WestBank Roofing to Begin Planning Your Roof Conversion or Replacement Today

When it comes to choosing a roof, the most important things to consider are aesthetics and the needs of your property. Choose a style or material that clashes with your building, and your curb appeal may plummet. Install a design which doesn’t suit your area’s climate, and you may find yourself paying for extensive maintenance and repairs. 

Deciding between a flat roof and a pitched roof can be convoluted, but thankfully, Southeast Louisiana property owners have a skilled contractor on their side. Our team at WestBank