What is a Skillion Roof?

Published: Nov. 1, 2018
Modern house with skillion roof

A skillion roof has one single flat surface. It cannot be compared to a standard flat roof because the pitch of a skillion roof is steeper and noticeable. A skillion roof is also known as a mono-pitched or shed-style roof. The single-sloped surface of a skillion roof is not attached to another roof surface, making it quite different from a dual-pitched or gable roof. Skillion roofs are easy to construct and present a minimalist, unique look.


It is unclear as to where and when in history, skillion roofs were prominent but we do know the skillion roof was a common roofing style that was used for home extensions in the Victorian times. Skillion roofs were used in areas that were prone to less rainfall and were better suited for warmer climates, hence their name shed-roofs. However, thanks to modern design and innovation in the choice of materials, skillion roofs can be used to cover a variety of different sized structures and are not bound to small shed-like structures alone.

How are They Built?

Skillion roofs are generally standalone roofs. They do not need to be attached to any other part of the roof. While traditional roofs generally tend to have varying slopes and pitches, skillion roofs are simpler to construct. A structure can have both a skillion roof as well as another roofing style.

A skillion or mono-pitched roof has two main parts:

The Rafter: The rafter is the sloping member that is used to form the roof’s pitch. It is typically used to provide support to the roof. It is also used to transfer the loads to the structure’s outer wall, thereby offering durability and support. Sometimes, in accordance with the length of the rafter, a beam is required to prevent the rafters from deflection and provide them with added support. A “bird’s mouth cut” on the rafters enable them to be connected easily.

Beams: Beams are also an important element of skillion roofing. In a skillion roof, beams are placed to run horizontally at a 90-degree angle with the rafters. The beams are used to provide the rafters with support and thereby strengthen the construction.

How Long do these Roofs Last?

Pitched roofs tend to last longer than standard flat roofs. If a skillion or mono-pitched roof has been constructed using quality materials that are both weather-resistant as well as durable, it will easily be able to offer a longer lifespan than a flat roof. A skillion roof that has been properly constructed with effective insulation will remain unaffected by extreme temperature and will require far less maintenance.

Advantages of a Skillion Roof

  • Easy to Build:

Skillion roofs require fewer materials and are easier to build than traditional roofs. However an experienced roofer will ensure that the skillion roof has been built using the right materials and has been constructed with precision and accuracy.

  • Cost-Effective:

Skillion roofs are ideal for those that have a limited budget since they are easy to construct and use fewer materials.

  • Added Value:

The ability to add multi-levels to a property using various skillion roofs provide a unique design and add value.

  • Simple, yet Elegant:

Skillion roofs have an angled flat surface and a rather noticeable pitch. This aspect of the roof catches attention and provides a minimalist yet elegant appeal.

  • Water Drainage:

Skillion roofs have a steep pitch that makes it easier for snow and water to run off the roof. This aspect makes them ideal for regions prone to high rainfall and snow.

  • Extra Cover:

Some homeowners may decide to make extensions using a skillion roof that can be used in addition to a traditional roof for extra cover.

  • Energy- Efficient:

The slight sloping angle of a skillion roof is the perfect surface for installing solar panels. Not only will solar panels help in saving energy they will also make maintenance easier in the future.


  • Limited Space:

Skillion roofs emerge at a constricted angle from the walls and ceilings of the property. As a result, space is constricted and offers less room for an attic.

  • Low Ceilings and Wind Hazards:

Ceilings in the property can be too low if the roof of the skillion roof is too high. Skillion roofs are also not a suitable option for areas prone to high winds.

Variations of Skillion Roofs

Variations of the skillion roof include oval and circular-shaped designs as well as other designs.

The butterfly skillion roof is also a popular roofing option that consists of two skillions or sloping panels that angle downwards in opposite directions, giving the impression of “wings.”

Curved roofs are also a variation of skillion roofs but are usually seen on large architectural buildings due to their high costs.

Homeowners can also combine both gabled roofing and skillion roofing in the same property. These roofs are known as split skillion or split mono-pitch roofing.

Price of Skillion Roofs

Skillion roofs are generally built upon rafters but cost considerably less than roofs that feature multiple slopes. A fair estimate for a skillion roof is anywhere from $6000 to $12,000 depending on various factors like the pitch and the materials used to build the roof. A skillion roof covered with asphalt shingles would cost far less than that of a skillion roof covered in metal. Installation costs also vary and depend on the slope of the roof as well as the number of rafters and beams being used.