Pergolas are one of the most interesting and useful home improvement projects a do-it-yourselfer can build. A well-built pergola provides beauty and function, and potentially adds value to a home. Building your own pergola can be a very rewarding experience for the average handy person who has a few tools and know-how.
What Are Your Building Options?
Pergolas are usually constructed from pressure-treated lumber, or some other rot-resistant material such as cyprus, redwood, aluminum, and fiberglass. Kits can also be purchased for the homeowner who is more interested in the assembly than a custom design.
These kits will contain all the lumber and hardware required for the build, along with detailed instructions. However, modification of the kit will often be prohibited, or at least limited. Either method will produce a useful and attractive addition.
There are several advantages to building your own pergola from scratch, but the most obvious benefit is the design. Custom building your own pergola to your own specifications is rewarding but also requires the most skill. If you are handy, experienced with tools, and up for the challenge, doing it yourself can save you money.
Kits are available for those folks that want the satisfaction of building their own pergola, but perhaps do not have the experience, nor skills required to build one from scratch. Others may just have limited time available and prefer to skip all the cutting and measuring. Regardless, pergola kits are usually well designed and fairly easy to assemble.
An attached pergola will have one or two sides permanently attached to an existing structure, such as a house or garage. This design has the benefit of generally fewer materials, but will involve modifying the existing structure. Depending on the exterior of the structure (brick, vinyl siding, etc.), an attached pergola can often be finished to look original.
Ready-To-Use Pergola Plans
Another option is to build your pergola from scratch, but with a set of professionally designed plans. This method allows the DIYer to cut and construct all of the parts of the pergola without the fear of making a design mistake. These plans will usually provide a materials list, all the measurements, and detailed assembly instructions. For the occasional handyperson, this method may be best.
Uncommon Pergola Designs
There are as many pergola designs as there are designers, but a couple of common styles are the corner pergola and a cantilevered pergola. A corner pergola, as the name suggests, is three sided.
This design is common where space is limited. Another popular version is the cantilevered pergola. These are popular when space is very limited and utilizes only two posts. As such, the rafters are extended beyond the footprint of the pergola and cantilevered, or supported on one end only.
Another option is to build a metal or fiberglass pergola. These are usually built from kits and offer benefits such as extra rigidity and low maintenance. Although these kits are readily available, the materials are more difficult to work with, so this type of build is better suited to the advanced do-it-yourselfer.
What You Need Before Starting to Build Your Pergola
Building a pergola, whether from scratch, a kit, or just a set of plans, will require some common carpentry tools and the experience to use them safely. Below is a list of common tools required for this project, but your design may require others as well:
- Circular saw
- Bar clamps
- Drill with both wood and masonry bits
- Carpenter’s square or speed square
- Nylon string
- Shovel and post hole digger
- Wheelbarrow, mixing pan, or large bucket
- Handsaw or reciprocating saw
- Jigsaw (if your design includes curves)
- Tape measure
- Pencil or marker
- Wood chisel
- Socket set or wrench
How to Build a Standard Wooden Pergola
As with any home improvement project, avoiding injury is always job one. Make sure that you have eye and ear protection, gloves, and any other safety gear (such as steel toed boots) you feel is necessary. Also consider having help readily available.
Today we will discuss the typical strategy and methods used to build your pergola from scratch. We will be discussing a free standing, four sided pergola, but if your design has only two or three sides, the process will be basically the same.
Although using joinery to connect the pieces together is an option, this method requires advanced carpentry skills. Today, we will only discuss the hardware method. If you are using a kit, some of these steps will have already been done for you.
Step 1. Location
Any permanent structure will need a footprint, so the first step is to decide where your pergola will go. This will be determined by your available space and the prevailing building codes in your area.
Some jurisdictions will require a permit, and others may not. Just keep in mind where your lot lines are and the required setback for your area. Also, consult your architectural committee if you live in a restricted subdivision, as some will prohibit outdoor structures.
Step 2. Layout
After you have your location selected and your required approvals, you can begin your layout. This is essentially the footprint your pergola will live on, so you want it to be as accurate as you can make it.
To begin, use small lumber (usually 1” x 4” or 2” x 4”) and create batter boards. These are sharpened pieces of wood driven into the ground in a triangular pattern, perpendicular to each other.
Repeat this process on all four corners. On one of these boards, mark a line that is perfectly level, and using either nylon string or a laser level, transfer this mark to the remaining corners.
Attach a horizontal board to this mark, and again, repeat on the other corners. Using the nylon string, drive a nail on this mark, twist the string around the nail and extend this line to all four corners. This creates the footprint for your pergola.
Step 3. Foundation
After the footprint has been established, use your level to make a plumb mark on the ground. This will be the location of your post hole. The size of the hole will be determined by the size of your post, so the rule is to make the diameter of your hole twice as large as the post.
For example, an 8” x 8” post will need a 16” diameter hole. The depth of the hole will be determined by the frost line in your area. This is the depth to which the ground freezes in winter. Your local codes official will have this information.
After your holes are dug, you are ready for concrete. In some jurisdictions, you can simply drop your post into the hole and add concrete, but we’ll use hardware instead. Place an appropriate sized concrete form into the hole and level it using the nylon string.
Make sure that all four forms are precisely the same distance from the nylon string. Now, mix your concrete and fill the form to the top. A smooth finish will allow your post to sit firmly.
Step 4. Install The Posts
The best way to attach the posts to the concrete is with hardware connectors. Several companies manufacture brackets specifically for this purpose. Each will connect to the concrete differently, so follow the directions for your hardware.
You will want these connectors to be plumb with your string and square to each other. This will ensure that your posts will not need to twist to perform the next step.
Before installing your posts, you’ll want to build some bracing. This is done by driving a short, sharpened 2” x 4” into the ground and attaching another full length 2” x 4” to it at a 45-degree angle, allowing it to pivot.
Do this in both directions. Using your level, plumb the post in one direction and attach one brace to the adjacent side. Then, plumb the post in the other direction and repeat for all four posts.
Step 5. Set The Beams
The beams you select will need to be large enough to support the structure and any additional loads, such as snow. These beams will connect the structure together, so accuracy will pay big dividends. These beams will typically only be on two parallel sides of the pergola and the rafters will sit perpendicular on these beams. The beams and rafters will often have decorative notches and curves cut into the ends as well. If your design incorporates these design elements, cut them before installing the beam.
Pro Tip. Make a mark on each post to indicate the eventual location of the beam and temporarily nail or clamp a piece of scrap lumber to that mark. This will help support the weight of the beam while you connect it to the post.
To connect the beams to the post, drill pilot holes all the way through the beam(s) and post and drive a weather-resistant carriage bolt into the hole. Secure it with a flat washer, lock washer, and nut. Repeat this process on the other side.
Step 6. Install The Corner Braces
For the pergola to be strong, diagonal bracing is usually needed between the posts and the beams. Simply nailing or screwing them together is not enough, as these fasteners will eventually fail. To build this brace, use lumber the same thickness as the beam and cut 45 degree angles on both ends. Connect it to the post and beam using weather-resistant carriage bolts or lag bolts. Repeat this process on two adjacent sides of each beam.
Step 7. Set The Rafters
After the beams and braces are in place, it is time for the rafters. The rafters will make up the bulk of the roof, so lay them out carefully. Generally speaking, the roof will get the most attention, so the design possibilities are almost endless. As such, we will not go into much detail here, but the basic function of the rafters is to tie the entire structure together.
Step 8. Attach The Louvers
Not all pergolas will have louvers, but many will. These louvers function as a lattice, and many owners will grow vines and flowers over it. The louvers do not need to be structural, so many builders will use small, inexpensive lumber. However, remember that every component of your pergola must be rated for outdoor use, including the louvers. Simply cut the louvers to fit and attach them perpendicular to the rafters.
Pro Tip. These louvers are usually thin, so make a small pilot hole in each fastener location. Otherwise, chances are very good the louver will split during installation and will have to be replaced.
Step 9. Apply Any Finishes
If you are planning to paint or stain your new pergola, do not attempt to do so on wet lumber. Pressure-treated lumber is usually still wet from the chemicals used during the process and must be allowed to dry before applying any finishes. This includes waterproofing. If you intend to use a finish, it is recommended to wait at least a year depending on the climate in your area. Another option is to use kiln-dried, pressure-treated lumber. Just as it sounds, this lumber is dried (to a point) at the factory, which eliminates much of the wait. However, kiln-dried lumber is more expensive, so if your pergola is large, the cost could be substantial.
Beauty and Function Combined
Building your own pergola is a great place to hone your carpentry skills. The process is much like building any structure, so if you have ever built a gazebo or a treehouse, building a pergola is probably within your skillset. If you enjoy working with measurements, power tools, and maybe a couple of friends, this project is for you.
How Can You Save Money When Building a Pergola Yourself?
- The most obvious way you will save money is by providing your own labor. The labor expense is usually around half of the total.
- Especially with lumber prices on the increase, measuring accurately will also have a dramatic effect on the overall cost. You can expect a small amount of waste, but mis-cuts can get expensive.
- Having a good plan will also save not only money, but time and effort. Changing your mind in the middle of construction will often lead to additional materials expense.