san francisco butterfly roof

What is a Butterfly Roof?

The type of roof that is V-shaped, resembling a butterfly, is aptly called a “butterfly roof.” It can also be referred to as an “inverted pitch roof” because the sides of the roof slope inward toward each other rather than rising to a point in the middle like a gable roof.

This type of roof came about in the 1950s, when architects began making bold design choices and were moving away from traditional gable and hip-roofed homes.

Butterfly roofs are very popular in Hawaii, where their ability to collect rainwater is a big draw. Even though Hawaii is made up of islands, the amount of rainfall varies greatly between regions. Making use of what falls is essential in some areas.


Water collection in arid climates is still essential. Even in Edmonton there are days or weeks when we’re asked to conserve water, so a roof that is good for gathering water would be easier on our water supply and our wallets.

Butterfly roofs are aerodynamic, so even if you’re not channelling the moisture for later use, the water will run right off. Another advantage to the butterfly roof is it allows for large windows on the structure’s high outer walls, which creates an open, airy feel.


The major drawback associated with butterfly roofs is the cost. Since the design is complex, it is more expensive than simpler roof designs.

Another disadvantage that comes with the butterfly style roof is that if the roof is not completely waterproof, you may experience leaks, especially in the valley of the roof where water may pool because of clogged drains.

Roofing Materials to Use for a Butterfly Roof

Ensuring that a roof is waterproof is always essential and it’s even more important for a butterfly roof. Using roofing material that consists of large sheets is ideal, so when building a butterfly roof, the best roofing materials to use are metal sheet roofing, modified bitumen, or a thermoplastic membrane.

Roofing Materials not to Use

Waterproofing is the main concern with a butterfly roof. So, the worst roofing materials to choose when covering it are ones that have a lot of seams, like slate roofing or clay tile roofs where each piece is installed individually. Wood shakes and asphalt shingles should also be avoided.

The butterfly roof is a mid-century classic that originated in The United States. That said, it’s a great option for home builders and buyers in Edmonton because of its eco-friendly design.

Its typically low-sloped surfaces are ideal to install solar panels on. Also, the valley in the center can channel water for household use.

If these benefits, in addition to a cool-looking design appeal to you, the butterfly roof may be the one to go with.

Looking to get your roofing questions answered? Give us a call at (780) 466-1601 or contact us today using our online form!