Bonnet Roofs Explained

A bonnet roof features a double slope on all four of its sides. The lower slope is less steep and more angular than the upper slope and extends over an open-sided raised porch. The design of the roof offers great shade and protection. The roof’s design is an opposite to the standard mansard roof due to its upper slope being far steeper than the bottom slope. Bonnet roofs are also known as a kicked-eaves roof. Kicked eaves are a roof enhancement that gives the home a visor effect. Modified gable roof, modified hip roof and a belcote roof are also common names for a bonnet roof. Bonnet roofs are generally seen on homes that have porches around the perimeter of the building.

History of Bonnet Roofs

Bonnet roofs date back to the 1700s. At the time, Polish and German people built their greenhouses with bonnet style roofs. These roofs helped protect the plants. The bonnet roof also gained popularity in the 1700s due to the influence of the Creole architecture around the Mississippi River area. Despite having a long history, bonnet roofs are still popular and can be found on ranch houses, cottages and mountain retreats. Although bonnet roofs were not commonly used in modern architecture, they can still be seen on modern homes too. Bonnet roofs are mainly found in the French Vernacular and can also be found in the Louisiana region.

Construction

Constructing a bonnet roof is comparatively challenging as compared to other roof styles. The complex design also adds cost. Specially designed trusses need to be put into place and the process needs to be done accurately to ensure safety and durability. Different from a traditional hip roof, the bonnet roof has a vertical triangle above the hipped end. The construction makes use of a compound truss at the bonnet position. The compound truss supports the mono-pitch trusses. In some bonnet roofs, the roof is supported by using timbers on the gable end of the roof.

How Long do They Last?

Bonnet roofs can be made from shingles, metal as well as natural stone. The lifespan of bonnet roofs depends on the materials used as well as the quality of labor work and requirements of the customer. Most residential homes with bonnet roofs are covered with asphalt shingles. However, asphalt shingles are not the best option when it comes to durability and low maintenance. For those wanting to get the most out of their bonnet roofs, covering the roof with metal is highly recommended and can last the lifetime of the building. Though metal roofing costs more than wood shakes and asphalt shingles, it all pays off in the long run.

Advantages

• Suitable for High-Wind Areas:

Areas prone to high winds and hurricanes are ideal for the installation of bonnet roofs. In comparison to gable roofs, bonnet roofs are less likely to get damaged and torn off due to wind pressure.

• Better Protection:

Low-sloped sides of bonnet roofs protect the building from the harmful rays of the sun as well as from water damage. The low-sloped sides assist in keeping the house and the porch area cool in the warm weather.

• Extra Living Space:

The upper slope of the bonnet roof offers additional living space that can be utilized into a small attic. Side windows and dormers can also be used for extra lighting.

• Gutter Installation:

The design of a bonnet roof proves favorable for gutter installation and makes it easy for the builder.

Disadvantages

• Increased Costs:

Bonnet roofs require additional building materials like trusses that add to the material and installation costs.

• Maintenance Issues:

Water can easily run off the slopes of a bonnet roof, however, valleys can be formed at the intersection of the two slopes. Extra precaution is required to waterproof these areas during construction of the roof.

• Not for Everyone:

Bonnet roofs have a distinct look that is not for everyone. Modern architecture enthusiasts may find the design of a bonnet roof to be a bit outdated.

Variations of Bonnet Roofs

Pyramid Hip Roof:

In a pyramid hip roof, all four sides of the roof are triangular and equal. The four triangles join up to a single point to form the pyramid shape of the roof.

Simple Hip Roof:

In a simple hip roof, all sides of the roof slope downwards to the walls. These roofs are perfect for buildings that have two sides longer in length compared to the other sides.

Dutch Gable Hip Roof:

A hybrid design of a hip roof and a gable roof is called the Dutch gable hip roof. This type of roof has a small gable at the top of the hip roof.

Crossed Hip Roof:

A cross hipped roof is formed by merging two hipped roof buildings together. The roof has two intersecting hip sections that are perpendicular to each other.

Pricing

The price of bonnet roof varies according to the requirements of the customer. Factors influencing the cost include the size of the roof, materials required as well as installation and maintenance costs. Bonnet roofs made of metal cost more but work out to be almost maintenance-free since they offer increased durability and stability to the building. Metal also helps seal out water and offers protection against fire.