All About Gambrel Roof: Calculation, Implementation, How to Build, Pros and Cons

Gambrel Roof – A gambrel roof is a symmetrical two-sided roof in which each side has two slopes, one steeper and one shallower. Think of a typical barn roof, the most common gambrel roof most people see.

This style is also a standard roof design found in Dutch colonial houses, and some historians suggest that early Dutch traders in Southeast Asia saw the style and brought it with them when they traveled to other places.

The peak of a standard gambrel roof is normally built at a 30-degree angle, with the second slope at 60 degrees, but (as with so many things) it can be customized according to an individual builder’s wants and wishes.

Gambrel roofs are easy to build and they offer more storage space under them than typical pitched roofs (the triangular roof shape we see so often).

They also require less materials to build than roofs with extra support beams and columns. Because the gambrel provides more space, they are often seen on storage sheds, barns, or other similar structures.

Gambrel roofs used in houses and residential buildings often include a dormer (an additional space that juts out from the building with its own roof parallel to the larger roof) and double-hung windows to allow light into the space.

Origins of Gambrel Roof Designs

Gambrel has Latin origins where the word’ gamba’ refers to the leg or hock or a horse. It likewise has an American and also European beginning which basically describes a curb roof.

Despite the difference, Europeans had a hard time setting apart mansard and also gambrel roofs and jointly utilized the exact same term for all of them. Today, there are a few variations of gambrel roofs such as Dutch, Dutch Colonial, Swedish, German- English, New England or French gambrel roofs.

Besides gambrel as well as mansard roofs being similar, they have different cross-sections. For instance, for the gambrel, there is an upright gable as opposed to one that’s hipped at 4 edges like the mansard. Also, unlike the mansard, the gambrel roof overhangs at the facade.

When It Comes To North America, the origins of gambrel roof designs are unknown. In America, the earliest layout was constructed in Harvard University as far back as 1677.

Peter Tufts House circa 1677 to 1678 is the earliest residence in the U.S with a gambrel roof. The Fairbanks residence, the earliest framed residence enduring today additionally has a gambrel roof yet this was included later on.

There are a few insurance claims to the origins of gambrel roofs in America. Initially, there were Dutch, Spanish, English as well as Portuguese investors and seafarers that resolved in Southeast Asia (Indonesia) before working out in Europe as well as later America.

When in Indonesia, they experienced homes constructed with roof designs where there was a hip at the start as well as finished with a gable discovered on the ridge.

The gable located at the end was simply acting like a smokeshaft to dissipate smoke from any kind of fires lit inside for food preparation functions.

Obviously, these designs were brought back to Europe and America as well as presented by regional building contractors. There are various parts of the world that still use this roof layout up to date.

Secondly, there are gambrel designs initially discovered in Netherlands that were reminded America by seafarers. Finally, these roof designs were introduced for reasons such as allowing large buildings, utilizing short rafters or as a means to evade paying tax obligations.

The Pros and Cons of Having a Gambrel Roof

All About Gambrel Roof: Calculation, Implementation, How to Build, Pros and Cons

A gambrel roof has two slopes, out of which one is steeper and the other is shallower. The named gambrel is derived from the back portion of a horse leg or ankle of a horse.

The roof is commonly seen in houses and large farm buildings. These roofs are easy to frame and have an excellent drainage capability.

Pros of Gambrel Roofs

Past legacy – During the era of colonial America, this was the standard roof used by the Dutch and Georgian style homes. Thus, people following this roof design are associated with either of them.

Easy built up – The roofs can be easily constructed and allow more space for an upper floor. The roof is simple to frame out. The conventional Gambrel roof uses two roof beams, but employs simple gusset joints.

Cost – These roofs are not only easy to build. However, they are time and cost saving too.

Style – The roof has two curved lines that present an uncomplicated and stylish look. The unwavering style looks satisfying and fashionable.

Cons of Gambrel Roofs

Weather – These roofs are not ideal or advisable in areas that experience snowfall, heavy winds, and heavy breezy weather as it is not tough enough to handle the pressure.

Durability – Gambrel roofs demand frequent maintenance. They need to be made durable, painted and protected on a time-to-time basis.

Facing – South facing heavy winds and rain can harm the roof top area.

Discrimination – It is not very easy to differentiate between gambrel roofs and bold roofs that posses change in affix designs.

Calculation Tips for a Gambrel Roof

Calculation Tips for a Gambrel Roof

A gambrel roof design is a very distinctive attribute of any barns, sheds, and outbuildings. While the gambrel roof design is used for homes as well, it is mostly found in large barns and garages because of its strength over a large area.

If you are thinking of a building project that involves a gambrel roof design, here are a few tips to help you calculate the angles.

Four Angles Needed

With the gambrel roof design there are four angles that are used to make up a total of 180 degrees. Depending on the size of the roof, and the pitch of the roof, these angles will change.

You want to try and use angles that are as close to 45 as you can get for both ease of construction and good strength.

Width vs. Height

A good rule to follow with a gambrel roof design is that is should be twice as wide as it is high. This will give not only a symmetrical appearance, but also balance out the load of the building over a much more stable area.

Lower Pitches

Typically a gambrel roof does not have an extreme pitch to it. This is because when you have too much of a pitch you will need to go very high with the roof. Keeping the roof pitch low to a 12/12 pitch will give you much easier angles to work with.

Gambrel Roof Implementation

Gambrel Roof Implementation

The gambrel style can be implemented in many ways into a roof design such as:

  • Gable gambrel
  • Dormer gambrel
  • Valley gambrel

Construction of a Gambrel Roof

Construction of a Gambrel Roof

A gambrel roof is framed out, which means that the builder constructs a series of individual trusses with the identical measurements. This can be done with wooden two by four boards assembled on the ground or a flat surface.

Each side of the roof truss has two roof beams that are reinforced with a simple gusset plate (a triangular wood or metal plate that reinforces the joint, usually screwed into place).

When all the trusses are done, they will be raised into place on the top of a building and secured to the floor. The trusses are then covered with the roof deck, which could be composed of wood, metal siding, or shingles. The number of trusses needed depends on the size of the roof being built.

How to Build a Gambrel Roof

How to Build a Gambrel Roof

If you are building or renovating your house and would like to have more storage space than you used to, you can try erecting a gambrel roof, which with its arch shape, will provide ample room to store your possessions.

Read on to find out the steps to follow if you decide to beatify your home with this stylish yet practical type of roof.

Step 1 – Plan the Gambrel Roof

The first thing you should do is calculate the trusses you will need. The trusses of the roof should be 16 inches apart from one another.

Decide how high the gambrel roof will be. For example, a good height for a 36-foot wide building would be 10 feet 4 inches, but there are no restrictions.

Ultimately it is up to you how tall the roof will stand. Just remember when making the calculations that the upper section of the gambrel roof typically has an angle of 30 degrees, while its lower part is slanted at 60 degrees.

Step 2 – Lay Out the Trusses

Buy the boards you will need for the construction. (The most appropriate will be 2-by-6-inch boards.) On a level plot of land, lay out four boards in a design of your choice and mark with chalk the places where you will cut and the angles you will need for the roof.

Make the cuts and use the boards as templates for the other trusses. Then take some cardboard and trace the truss angles onto it. Use the resulting patterns to create brackets from 1/2-inch plywood. You should come up with two bracket shapes–triangular and doglegs-like.

Step 3 – Assemble the Trusses

After you have cut the boards and brackets for the trusses, you need to join them together. Attach the brackets by using eight penny nails. If you aim at further reinforcing the joints, tie them with metal straps. To finish the trusses, take a 2-by-6-inch board and secure it between the dogleg brackets to serve as a joist.

Step 4 – Lift the Trusses into Place and Cover Them

Raise the trusses into position and having made sure each truss is plumb and straight, nail them to the joists of the lower floor.

Have a temporary brace fixed between trusses while you are building the roof. In this way the trusses will not tilt sideways and will form a strong foundation for the roof.

For roof sheathing, cover the trusses of your gambrel roof with 3/4-inch plywood and secure it in place. (If you live in an area with heavy snowfalls, increase the thickness of the plywood.)

Place a layer of waterproof material over the plywood and finish working on the gambrel roof with shingles of your choice.

Step 5 – Build the End Walls

Cut studs for all end walls and fit them within the slope of the roof by cutting angles into the studs and notches into the angles and trusses. If you want, frame and install windows. Finally use plywood and shingles to cover the ends.

Gambrel Roof Shed vs. Gable Roof Shed: What’s the Difference?

If talking about gambrel roof, then of course we will talk also about gable roof. Do you know what is a gable roof? and what’s the difference with the gamble roof? Ok, let’s discuss it all.

Gambrel Roof Shed vs. Gable Roof Shed: What’s the Difference?

What is?

  • Gambrel Shed Roof

The gambrel roof shed, or mini-barn, has two main slopes per side. The steeper slope, at the sidewall, gives you a bit more headroom close to the wall.

  • Gable Shed Roof

The gable roof shed is also known as an A-frame roof, or “cottage” style. This one looks more like a house, which is something many people find attractive.

Shed Wall Height

Roof line is important. But the side wall height of your shed makes a significant difference both in storage space, and in cost. The wall height of cottages and mini-barns varies from 4 ft high (for our low-wall barn) to normally about 7 ft high for cottages and hi-wall barns. (Of course, if you’re willing to pay the price you can go as high with your wall as you want.)

  • Gambrel Shed Roof

The low-wall barn with the shorter wall is usually less expensive. It offers better value per square foot of floor space. Low barns can only accommodate windows and doors in the ends of the buildings, for obvious reasons. Also, shorter walls = fewer shelves.

  • Gable Shed Roof

The high-wall barn costs more than a cottage of the same size. But you get more overhead storage space. And, high wall barns can have windows and doors on the sides, not just on the ends.

Gambrel Roof Designs

Check out our pictures of homes with gambrel roofs below to get a sense of the many gambrel roof designs you can implement.

Gambrel Roof Style House Plans

Gambrel Roof Style House Plans

Gambrel Roof Style House Plans

Gambrel Roof Style House Plans

Gambrel Roof Style House

Gambrel Roof Style House Plans

Gambrel Roof House Plans

Gambrel Roof House Plans

Gambrel Roof House Design

All About Gambrel Roof: Calculation, Implementation, How to Build, Pros and Cons

Gambrel Roof Style Steel Buildings

All About Gambrel Roof: Calculation, Implementation, How to Build, Pros and Cons

Gambrel Roof Garage

All About Gambrel Roof: Calculation, Implementation, How to Build, Pros and Cons


1 thought on “All About Gambrel Roof: Calculation, Implementation, How to Build, Pros and Cons

  1. A gambrel roof is a two-sided roof with two slopes on each side, one steeper and one shallower. While every kind of roof has its own structural and functional advantages, you should first research on different types of roof to be able to decide wisely.

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