Lyons Roofing

How Are Flat Roofs Different from Pitched Roofs?

There are two different types of roofs: steep sloped (pitched) and low slope (flat). Obviously one type of roof has significant slope to it while the other looks nearly parallel to the ground below (Flat) the truth is even “flat” roofs have slight slope to allow for drainage, but there are some other important differences between these types of roofing which set them apart from each other. In fact, their construction, care, and maintenance are all dramatically different from each other. On this blog, we’ll take a look at several important differences between these different types of roof.

Common Usage

Both types of roof can be used for both residential and commercial buildings. However, flat roofs are far more common for commercial purposes than steep roofs, whereas steep roofs are generally found more frequently in residential applications. This is because many commercial structures mount a number of things on their roof, including solar panels, HVAC equipment, refrigeration equipment, and much more. When more flexibility and versatility is needed, a flat roof is going to serve the purpose far better than a sloped one.

Conversely, homeowners generally only tend to mount solar panels on their roofs, and solar usually benefits from using the slope to its advantage anyway. That being said, many modern homes are starting to utilize flat roofs for their aesthetic qualities.

Common Materials

You’re probably well aware of the different types of materials that can be used for steep roofs. In the southwest and all across Arizona, clay and concrete tiles are extremely common roofing materials because of their fairly low cost and unparalleled durability when it comes to surviving the harshness of the sun and scorching triple-digit temperatures. In other areas across the country, asphalt shingles, wood shake, and even metal like copper and galvanized steel are common steep-roof materials.

For flat roofs, the selection of materials is considerably more diverse and less well-known. Built-up roofs are one of the most common types in the Southwest because of their durability to UV radiation and heat, but they’re fairly difficult to install and on the expensive side. You can usually identify a built-up roof by its top layer of gravel and small rocks placed over a thick seal of asphalt tar.

Another common flat-roof material Polyurethane Spray foam roofs. These roofs are lightweight, easy to install, and because it is sprayed as a liquid that quickly “sets” into a durable closed cell roofing system it is seamless and chemically adheres to all roof penetrations where most leaks happen over time. Spray Foam is an extremely popular material for major commercial and industrial buildings such as warehouses and factories. The foam itself acts as another layer of insulation above the roof line, likewise, the white color is reflective of sunlight and helps keep the area underneath cooler, which can go a long way to saving energy and money during the heat of summer. May residential homes use foam over livable areas because of the energy benefits of this product.

Leak Vulnerability

As mentioned earlier: there’s no such thing as a truly flat roof. A flat roof would be a disaster during rain or other inclement weather because water would continue to simply pool up on the roof, adding weight, and possibly lead to the roof completely collapsing. Instead, “flat” roofs are actually pitched at a very small angle and have drainage solutions installed so the water can easily leave the surface. Unlike a steep roof, however, the angle may be so small it might be hard to detect by eyesight alone.

That being said, flat roofs, even with this small slope, are far more prone to leaks. Sloped roofs are designed to divert water away from the roof as quickly as possible. The less time water spends on your roof, the less likely it is to wear away at the materials, slip through a small crack, and create leaks. Conversely, the low slope of flat roofs make them more vulnerable to ponding and other flaws which can lead to increased chances of cracking and leaking. In these instances, maintenance is the key.

Ownership Costs

Then there’s the matter of costs. Flat roofs tend to be less expensive to install than their steep counterparts because steep roofs have an inherently more difficult installation process that includes more risk. However, this could be a positive trade-off in the long run: flat roofs are generally more difficult to care for, require more maintenance, are more prone to leaking, and are more expensive to repair. Whichever roof you have, there are ways to minimize expenses- as we always say- the best cure for a leak is prevention.

Do you need your roof serviced? Whether steep or low slope, trust the Phoenix Roofers at Lyons Roofing! Call usat (520) 447-2522 to request an appointment now!