A gambrel roof is one that has two sides to it. Each one offers a shallower slope that sits above a steeper one. Most designs are symmetrical, providing the advantages of a sloped roof while still maximizing the amount of space inside of the building. This design is sometimes called a Dutch, Swedish, German, French, English, or New England roof. The original concept from Europe called this design a “mansard” roof.
The origins of this design are unknown in the United States. What we do know is that the oldest roof in America that uses this option is the second Harvard Hall at Harvard University, which was built in 1677. The oldest surviving house in the U.S. is Peter Tufts House, and it also dates to 1677. The oldest surviving framed house in North America, called the Fairbanks House, received a gambrel roof as a later addition.
Most barns and many stables in the United States use this design as a way to improve storage for agricultural products. Some churches use the concept to provide high ceilings.
If you’re thinking about a new house design or need to learn more about this concept, then these gambrel roof advantages and disadvantages can guide you through the various points you need to know.
List of the Advantages of a Gambrel Roof
1. It gives a structure a unique historical vibe that other designs can’t offer.
The gambrel roof is most commonly seen on large farm buildings and houses that date back to the colonial era of the United States. Using this design today can connect your property to the Georgian and Dutch styles that were so popular in the past. Even if your project involves new construction, the aesthetic association with the double-roof concept can provide more value to your structures. It can be an easy way to create something distinctive in your neighborhood.
There is a certain romanticism that develops around the idea of a gambrel roof. Although some people don’t like this design, the traditional shape and structure speak to our sense of culture in ways that a flat roof or another modern design cannot provide.
2. Fewer materials are necessary for its construction.
A gambrel roof requires fewer materials during the installation process. That’s because this design doesn’t require the same number of columns or support beams as newer construction methods. That means homeowners can spend less on materials and labor when creating the protective top for their structure. It only uses two roof beams, along with gusset joints, to create the final design. That’s why the cost of a gambrel roof can be significantly less than one with steep gables.
3. It is easy to build a gambrel roof.
Although the design of a gambrel roof looks like it would be a complex construction to complete, it really is a simple approach. This option works well in any situation where more space for an upper floor or higher ceiling is necessary. The simplicity of framing makes it a convenient method that any contractor can use. It is a cost-effective solution that creates extra space when other designs would require you to enclose the area. You can use the room for storage or finish it for additional bedrooms.
4. Gambrel roofs provide excellent drainage.
The steeper slope of a gambrel roof provides a structure with an excellent drainage profile during heavy precipitation events. It manages rainfall the best, as the water simply runs off of the side of the building without getting captured. That means there are fewer problems with sitting water, preventing leaks and damage events that can sometimes occur when using more traditional designs. That means your long-term maintenance costs tend to be a bit lower with this option.
You can also reduce the need for gutters and supplementary precipitation management systems with this option. It isn’t always a great choice in very snowy areas, but you can avoid the costs and materials of other needs.
5. It provides a structure with a long-lasting result.
When contractors use the correct materials when building a gambrel roof, then it can last for several decades when it receives regular maintenance. Most can last for well over a century before there is a need to start thinking about refurbishment. That means you can have a desirable structure that looks fantastic without breaking your budget. Considering the simplicity of its framing, you’ll discover that this design can be one of the best investments for new construction.
6. You’ll receive more space to use with a gambrel roof.
The reason why storage buildings and outdoor sheds use gambrel roof designs is that it creates more interior space to use. You can take up a limited footprint on your property while having the same out of room to use for your things. When you give the roof a robust layer of shingles and waterproof the edges, then you’ll maximize its durability while achieving the results you want to have on your property.
7. You can add windows to a gambrel roof design.
Many builders recommend that you add windows to your gambrel roof. It is an easy way for you to add natural light to the extra space that you’ll receive. This advantage can also add a lot of extra value to your home because it improves the visual aesthetics of the design. How you accomplish this benefit will depend on your geographic location. Some windows work better within the sloped section of the roof, while some areas do better when the windows are placed in the vertical support walls.
8. A variety of materials can get used to create a gambrel roof.
The material that gets used for a gambrel roof can include wooden shingles, slate, or asphalt coverings. Using metal can cut down on the amount of maintenance that’s needed for this structure, and anything suitable for use in your geographic region will work for your design. That means you can use today’s best materials to create the custom look that you want to have for your home.
If your property is in an area where extreme weather is possible, then reinforced trusses will help to cut down on your maintenance needs. You’ll want your builder to focus on the upper pitch to maximize the benefits of this design.
List of the Disadvantages of a Gambrel Roof
1. This roof design offers poor resistance to snow accumulation.
Even though the sloped design of a gambrel roof works well for rainfall when it occurs, the flatter upper portion of this option tends to accumulate snow in ways that a steeper angle wouldn’t collect. That means a heavy snowfall over a long time can result in enough pressure on this design that a potential collapse is possible. Unless you have ways to take the snow off of the top of the structure, anyone in a lake-effect area would want to consider a different option.
2. Weathering patterns can create uneven wear with gambrel roofs.
Because there is a strong chance that weathering will occur with a gambrel roof over time, there must be an annual maintenance check to ensure its stability and durability. If damage occurs over the course of the year, then the cost to keep up with this design can be more than it is for a more traditional approach. Contractors can reduce this problem by using metal and other sturdy materials during the installation process to reinforce trusses, but it must be an effort that happens at the beginning of the building process.
If you purchase a home with a gambrel roof, then you will want to focus some attention on the inspection process to ensure that the structure is sound.
3. It is challenging to retrofit a gambrel roof.
A gambrel roof is relatively easy to build during a new construction project. If you want to install one on an existing building, then it can prove to be an expensive concept to fulfill. Its unique shape proves to be difficult to install if the support structures aren’t already in place before building the roof. That means it isn’t an ideal option for someone wanting to upgrade their current spacing options or to convert a loft. You’d need to gut the entire upper section of the rafters to create the necessary shape.
It requires a specialized builder to complete a retrofit if you want to convert to a gambrel roof. Some homeowners may not have someone with the capability to do this work in their area. Even roofing contractors who are unfamiliar with this design should avoid any inspections or maintenance since it is such a unique option to use.
4. The gambrel roof can be susceptible to wind damage.
The size and shape of the gambrel roof can make it more susceptible to wind damage in some areas. This issue occurs because the aerodynamics of the structure don’t allow the air to move smoothly over the steep surface of its lower slopes. It is not unusual for severe wind incidents, like a tornado or hurricane, to create conditions where the roof gets lifted completely off of the structure.
Builders can avoid some of this issue by understanding local weather patterns when considering the direction of the roof. If you use a gambrel design that works in complementary ways to the usual storm patterns, then some of the risks can get tempered.
5. Builders need to waterproof most gambrel roofing design.
A gambrel roof requires waterproofing along its ridges to ensure that damage doesn’t occur with the seasonal precipitation in your region. If you get heavy snowfall or an excessive amount of rain that causes local flooding, then you’ll want to inspect the roof immediately to ensure that the integrity of your seals isn’t compromised. This issue becomes even more of a problem if you have windows installed in the roof to add some light to your extra space. The extra structure creates an additional place for a leak to occur.
6. There can be issues with ventilation in some designs.
Because most structures that use a gambrel roof take the open area as usable space, there can be some ventilation issues that occur. You’ll have less insulation available at the top of your structure, which means all of the hot, moist air from inside will rise. You must also account for the precipitation outside that attempts to seep in through the structure. Ventilation fans and other options can work to counter this disadvantage, but you may not have them available if you use this design for your outbuildings.
The gambrel roof provides homeowners with a stylish design that maximizes their space at the top of the structure. It can get completed for a low cost on a new build, and this design is suitable for many outbuildings that are necessary in the agriculture sector.
Buildings that use this design typically require an extra level of attention to ensure there are no maintenance issues developing. That means it is an option that works best in climates with temperate weather without precipitation extremes.
When evaluating the advantages and disadvantages of a gambrel roof, it is essential to understand the balance between durability and design. If there is excellent drainage that can prevent water damage and snow accumulation, then it can a positive addition to almost any property.
Brandon Miller has a B.A. from the University of Texas at Austin. He is a seasoned writer who has written over one hundred articles, which have been read by over 500,000 people. If you have any comments or concerns about this blog post, then please contact the Green Garage team here.