If you are interested in building your own pergola, the main design consideration is usually the roof. Pergolas have been around for centuries and go by many names. The words arbor, pergoda, and pavilion are often used interchangeably, depending on where you live.
Pergolas consist mostly of rafters, with posts and beams providing the support. These rafters often become the platform for climbing vines and flowers, creating a beautiful and relaxing environment. However, a pergola is generally considered to provide shade, not protection from the elements, so we won’t be discussing shingles and flashing, but rather the various rafter designs and benefits.
What Can I Build?
Which roof design you use will probably depend on the answers to the following questions:
- Will your pergola be free standing?
- Does your design require the pergola to be attached to the home?
- Will your design use gable, shed, or hip rafters?
Each of these common designs represents a balance of appearance, cost, and skill. A typical handyperson can probably design and build a shed style roof, while a gable or hip roof will likely require more experience.
The tools required will remain the same regardless of which style roof you build. Hip and gable roofs, however, will require compound miter cuts, which is cutting two angles simultaneously. If you are new to power tools, we recommend practicing first, or getting someone with experience to help you.
We will describe the three most common roof designs, why you may want one over another, and a brief description of each.
Tools You May Need to Build Your Pergola Roof
You will need a few carpentry tools, as well as safety gear. Below is a list of common tools required for this project, but your design may require others as well:
- Circular saw
- Bar clamps
- Carpenter’s square or speed square
- Handsaw or reciprocating saw
- Jigsaw (if your design includes curves)
- Tape measure
- Pencil or marker
- Wood chisel
- Sawhorses (2)
Steps To Build a Pergola Roof
As with any home improvement project, avoiding injury is the first and most important step. Make sure that you have eye and ear protection, gloves, and any other safety gear you feel is necessary to do the job without injury. We also recommend having help available.
Step 1: Design
The location of your pergola will determine what roof options are available. You will have the most flexibility with a free standing pergola, but unless you have a large deck, this may not be an option. Regardless of the location of your new pergola, get any approvals you may need before beginning your project.
Some jurisdictions may require a permit while others may not, so check with your local codes official. Also, we advise consulting with your architectural committee if you live in a restricted subdivision, as some prohibit any outdoor additions, or at least have guidelines to follow. With most pergola roofs, the rafters will have some form of decorative cuts or angles that complement the look. If your plan will have these embellishments, make them on the ground before installing them to make the job easier and safer.
Step 2: Layout
The layout of your pergola roof can be quite simple to very complex. An advanced do-it-yourselfer will likely have the tools and experience to build an elaborate roof, while others may prefer something simple. We’ll describe the most common (shed), to the more intricate (hip), and the basic differences.
Pro Tip. Regardless of which design you build, start with the straightest board you have and make a pattern for the rafters. This will be used to make all the other rafters uniform.
Shed Style Roof
A shed style roof is the simplest and easiest to construct. Think of a shed roof as one side of a gable roof. These are very common in older structures, such as barns, stables and birdhouses. This type of roof is flat with one side slightly higher than the other, usually the front being the highest.
This slope, or pitch, allows the roof to “shed” rain water efficiently. To begin, the required angle is cut onto all four posts, making sure the front posts are a few inches longer. Also, note that the angles on all of these posts are in the same direction, not mirror images of each other. The beams are then connected to the posts with galvanized carriage bolts, following the angle.
After the rafters are cut, they are laid out along the beams and fastened with galvanized screws. Care should be taken to make sure the spaces between the rafters remain consistent. If the design will also include louvers, they are installed with galvanized nails perpendicular to the rafters.
Gable Style Roof
A gable roof is the next simplest design, made popular in the earliest residential construction. The gable design is essentially two shed roofs joined together, sloping away from each other.
The building process is the same as with a shed roof, with the addition of a ridge board. This ridge board runs the entire length of the roof and represents the highest point on the structure. In contrast to a shed style roof, each side of a gable roof will be a mirror image of the other.
Hip Style Roof
A hip roof design takes a gable roof and adds another adjacent roof at a 90 degree angle to it. This style of roof became very popular during the 1980’s and is still widely used today.
The hip refers to the roof’s change in direction, so a hip rafter will divide two roof sections at 90 degrees to each other. The visual effect can be dramatic, so this design tends to be used most often on larger pergolas. As mentioned earlier, this style of roof can be complex to design, but will often produce the most attractive results.
Add Value and Appearance
As mentioned earlier, the roof of your pergola can have a large effect on the curb appeal of the project. Whether your design incorporates a shed, gable, or hip rafters, the goal is to build a functional, strong structure you can be proud of. Taking your time, doing your research, and working safely are key to the quality and functionality of your new pergola.