Flat Roof vs Pitched Roof

Is a specific slope for your roof better than another? Is a flat roof better than a pitched roof? What materials work best with steep roofs versus flat roofs? Jacksonville roofing companies and roofing companies around Florida get asked these questions all the time. Cache Roofing, a leading roofing company in Jacksonville, can help you decide all your roofing needs. 

What Is the Difference?

There is the obvious visual difference between a steep roof and a flat roof. A flat roof, while not actually flat, appears flat to the eye. There are a range of slopes that extend past 45-degrees.

The most notable difference, besides visual, is water runoff. The slope of a roof is the main factor for where and how water runs off the roof. Flat roofs will have a much different rain runoff outcome than a steep roof. In fact, many flat roofs have more issues with proper water drainage leading to water puddling and leaks.

The other notable difference is walkability. The steeper the roof, the more difficult it is for people/workers to walk on and inspect. This can mean additional tools are needed for inspections, cleaning, and repairs. Extra tools can mean extra cost. 

Regulations

There are minimum and maximum pitch codes. These codes vary depending on the materials used. The minimum slope is for proper rain runoff. Water needs to fully drain off the roof within so many hours or days to be considered up-to-code. There is also a fire code that dictates the maximum slope for individual materials. 

According to the National Roofing Contractors Association, building codes minimally require, “the drainage condition in which consideration has been made for all loading deflections on the roof deck and additional slope has been provided to ensure drainage of the roof within 48 hours of precipitation.” 

What Are Different Sloped Roofs Called?

We’ve covered flat roofs, but there are a plethora of other style roofs. The roofing calculator names many different sloped roofs: Lean-to, gable, dormer, hip, hip and valley, gambrel, mansard, butterfly, hexagonal gazebo, jerkinhead, M shaped, saltbox, shed, combination, pyramid hip. All of these have different slopes and work with different materials. 

The flatter the roof the fewer materials you have to choose from to build your roof with. Some materials work better with sloped roofs. Metal roofs work well with flat roofs. The common asphalt shingle roof is not recommended for flat roofs.  Many flat roofs use a rubber coating or tar coating to create a waterproof membrane.

 Medium sloped roofs such as gable, hip or combination styles can use almost any material. Barn, gambrel, or rainbow roofs work best with metal materials as well because these roofs tend to crumble “under heavy snow buildup and shaking in high winds,” the roofing calculator said. Extremely steep roofs work best with metal, tile, or slate roofs. 

Sloped Roofs and Weather

FEMA’s report on Roof Coverings and Best Practices explains that roof punctures are a big reason for roof failure during high winds and rain. Sloped roofs tend to stand up to roof punctures better than flatter roofs. “In most cases, debris punctures are less of a problem on residential structures were the roof’s slope limits the amount of rain that can enter a puncture (unless the puncture occurs in a valley or other areas of the roof where water is channeled or collected). However, in buildings with flat or low sloped roofs, punctures from wind-borne debris can be devastating,” FEMA said

This does not mean every sloped roof is safe from high winds. The roofing calculator explains that sloped roofs that have eaves can be vulnerable to high wind damage as well. 

Whatever the task, Cache Roofing can help you make the right decision for your home. Call Cache Roofing today. 

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