It is important to understand roof pitch, especially if you will be embarking on a construction project. Getting the right information beforehand will go a long way in helping you make the right decision on the best roof structure to use.

In the simplest terms, the pitch of a roof simply refers to the slope or steepness of a roof. Technically, the pitch measures the number of inches a roof rises vertically for every 12 inches in extends horizontally. For example: A roof is said to have a 4-in-12-pitch if it rises 4 inches for every 12 inches in runs horizontally. The slope is therefore basically a ratio of inches between the horizontal and the vertical over every 12 inches.

Here is a diagram that illustrates this.

Roof pitch

It is important to note that even a flat roof is not perfectly flat. It has a small degree of slope that allows water to drain off of the roof. They typically have a 2:12 slope.

Low slope roofs are roofs with a slope of below 4:12 while medium slope roofs are typically roofs with a slope between 4:12 and 8:12. Anything above 8:12 is considered a steep slope roofs.

The slope you choose will have a different effect of other factors. Here are some factors that will be directly affected. These are the factors to consider when selecting the right roof pitch for your construction project.

Cost of Roofing

The steeper a roof is, the more expensive and complicated it is to build. It will require specialized equipment and it is riskier on the workers. Scaffolding is required when dealing with steeper roofs, adding to the cost.

The slope will also affect the amount of roofing materials used. Steeper roofs for example, require more shingles than flatter roofs. It takes much more time and expertise to construct.


While steeper roofs are more expensive to install, they tend to be much cheaper to maintain. The steeper slope allows much better water drainage, leading to less damage over time. Flatter roofs on the other hand do not drain well and therefore and more prone to water damage.

Flat roofs are also usually walked on. Some people will even use their flat roof to create usable space on top of their houses. All these movement can lend a flat roof susceptible to damage, therefore pricier to maintain over time.

Roofing Materials

The slope of the roof will also have an impact on the roofing material to be use.

Flat or very lightly sloped roof cannot be roofed with shingles because the lack of pitch means the shingles do not drain water fast enough. This will easily lead to damage. Flat roofs require a roofing technique that is water proof. Gravel and tar become a better alternative for flat or nearly flat roofs.

SpaceRoof Pitch

One of the biggest advantage of flat roofs is the space created. Very flat roofs create additional space that can be put to good use. Of course this leads to more wear and tear and requires very good water proofing and maintenance. The extra space created makes the cost of construction and maintenance well worth it.

These are just a few factors to keep in mind when decided the best roof pitch to go for. Some people love the classic look of pitched roofs while others like the modern look of flat roofs. Visit our house plans gallery and see the different house plans we have with different roof pitches for your consideration.