Why is Determining Roof Slope Important?

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Why is Determining Roof Slope Important?

It’s probably something that you haven’t considered before, and might not need to consider unless you are having work done on your roof. If you are having work done, or having your roof replaced, then there is one very important thing you will need to consider: roof slope.

Ring any bells? Well, roof slope, also known as roof pitch, plays a vital role in determining what the best roofing system is for any given building, and is considered one of the primary deciding factors in roof design.

What is roof slope?

“Roof Slope” refers to the steepness of the roof, and is a measurement of the angle of the roof pitch. This measurement is determined by calculating, in inches, the vertical rise for every 12 inches it expands horizontally (known as the run). So, a roof can be classed from “low slope,” which will have a 2/12 slope to a “severe slope,” which will have a 12/12 slope.

Why is it so important?

Roof slope is important for a number of reasons. Firstly, it affects the volume of a building. Additionally, roof pitch determines which types of roofing systems and materials can be used for your building, and plays a role in determining how the roofing system performs long term and how long precipitation and debris can take to run off the roof.

When designing roofing systems, many manufacturers clearly mark the range of roof slope suitable for any given materials.  For example, tiles or composition shingles can only be installed on roofs with a roof slope of at least 3/12. This is because these materials need a slope of at least this severity in order to shed water and avoid damage.

If a roofing system is involved using materials that are incompatible with that roof’s slope, then the warranty may be void, and the ill-fitting roof can cause extensive water damage. This could potentially cost thousands of dollars to remedy.

Steeper sloped roofs are usually viewed as being more visually appealing than low sloped variants. Steeper sloped roofs also tend to last longer, due to the slope being ideal for allowing water to run off into the gutter and the sloped angle also stops the roof from being exposed to excessive UV rays every day.

Generally speaking, low sloped roofs are found on commercial roofing applications but are finding their way on to more and more modern residential properties, thanks to materials such as residential membranes, which help to increase the water protection of low sloped roofs. Low sloped roofs are energy efficient and low maintenance.

Comparatively, steeper sloped roofs cost more money upfront than low sloped roofs – due to the fact steep sloped roofs need a higher chimney and more materials to cover the increased square footage of the roof. However, due to low sloped roofs being more directly exposed to UV rays than their steeper counterparts, many people view steeper roofs as a more worthwhile investment as they generally last much longer than flatter ones.