How to Add a Pergola to a Deck: Tips and Considerations

This past spring, my wife and I made the decision to transform our backyard into a more welcoming, aesthetically-pleasing environment that we could both enjoy and use for entertaining. In fact, it has been part of a larger DIY home improvement project that I’ve mentioned in a few other articles on the topics such as choosing decorative metal brackets for wood beams and how to choose between a gazebo and a pergola.

So in one portion of the yard, we built a deck, but quickly realized that it would need something else, something more, particularly when it came to providing shade. At first, we bought a nice outdoor set with a table, chairs and umbrella. But we live near the coast, so we see strong winds on a frequent basis. As a result, it took about a week before that umbrella turned into a sail, toppling the table and causing the glass table top to shatter. It was clear that we’d need something more sturdy.

We went online to get inspiration and we ultimately decided that we’d build a pergola. Of course, I found that this task is one that’s much easier said than done. And there were a few lessons that I learned the hard way. So what considerations should you keep in mind when you add a pergola to a deck?

Determining the Size and Location of Your Pergola

As you get started with this project, you’ll want to establish a few key points. By answering each question below, you’ll be better prepared to proceed. Take some time to think about:

• How large would you like the pergola to be?
• Where exactly will you place the structure? Will its position adversely impact the flow of foot traffic?
• Will the pergola look like a cohesive part of your yard in terms of size, style, and positioning?

Ideally, your new pergola should not disrupt the natural flow of foot traffic on your deck. Think of the most common path that people take when walking across the deck (e.g. to the sitting area, to the grill, to the stairs that lead down to the yard, etc.).

If you’re uncertain about whether a particular pergola size or location will work, it can be helpful to use masking tape to map out the pergola’s footprint on your deck. If you prefer something more tangible, you can place chairs (or some other object) at each corner of the pergola footprint to represent the structure’s posts. If one side of the pergola will be a semi-solid trellis, you’ll want to run lengths of twine between the chairs to create a visual representation of that barrier.

Then, simply enjoy your deck as you normally would for at least a couple weeks, making note of whether foot traffic and other activities are impacted. You don’t want to lose functionality by adding a pergola; the objective is to gain functionality! So if you discover that you’re feeling overcrowded, you may want to change the dimensions and/or the location.

Selecting the Wood Species and Stain Color

Here’s brief summary of the basic steps you’ll want to take when it comes to deciding on wood type and color:

• Identify the species of wood used to build your deck
• Is the color of the wood for your pergola similar to the deck?
• Stand back at a distance to compare wood and stain colors

Ideally, you should select the same type of wood that was used to construct your deck so the new structure looks cohesive. This is important even if you’re planning to stain the new pergola because the finished result varies somewhat according to the color of the underlying wood. Of course, there’s a chance you may not know what species of wood was used to build your deck. If this is the case, you can still match the color as closely as possible. If it doesn’t match, it should, at a minimum, be complementary.

If you’re planning on staining and sealing the pergola, then you should stain a sample piece of wood to see how it looks on the deck. Stand back at a distance of 15 to 20 feet to get an accurate idea, because up close, it’s hard to detect slight differences. Keep in mind that it’s often better to choose a totally different wood or stain color instead of settling for a close but imprecise match.

Picking the Right Hardware

Few things scream “add on” like mismatched hardware. If your fence and deck have prominent silver-tone hardware and your pergola has hardware with a black finish, it’s going to lack cohesion. Some decks don’t have highly visible decorative hardware, so for these structures, you just need to ensure that your pergola’s hardware matches the overall style of your home. In other cases, you may have prominent decorative hardware on your deck, railing and nearby fencing. In this case, you’ll want to be sure that you match both the color and the style.

If you’re feeling extra adventurous, you can always swap out the hardware on your deck and railings to match your new pergola. Today’s modern pressure-treated lumber can easily outlast poor-quality hardware, making this a great option for updating your deck. In this scenario, you may opt for a complete deck and pergola hardware set that includes post bases, post-to-beam supports, rail saddles, rafter clips, truss accents and truss ties, truss base fans, and timber ties.

Other Considerations Before You Add a Pergola to a Deck

Before beginning the building process, you’ll want to think about a few other key issues:

• Will you require a building permit? Some municipalities will require you to secure a permit to build a pergola, so it’s wise to call your town or city hall to ask. Otherwise, you could be subject to a pretty sizable fine (which is usually three or four times what you would have paid for a permit).
• Can your deck support the weight of a pergola? An older deck may be ill-equipped to support the weight of a pergola, so this may be a good opportunity to replace your decking or deck posts with newer lumber. Decks over 15 years old or those constructed of untreated lumber are at higher risk of failure. If you have any concerns, it’s best to err on the side of caution by consulting a qualified expert like an engineer or contractor. You may opt to replace the decking or add some extra cross supports and posts on the underside of the deck.
• Will the pergola interfere with any doors, open-out windows, awnings, hot tub covers or other immovable objects? You’ll want to ensure that the pergola’s location and dimensions can accommodate immovable objects. There are few things worse than calling your wife to come see how your pergola is coming, but when she opens the back door, it slams into part of your handiwork…and she’s giving you “that look” as she’s forced to slither out through the foot-wide space.

There are lots of points to consider as you add a pergola to your deck, from selecting the right wood species or stain colors, to finding the perfect dimensions and positioning for this new structure and ensuring that your deck is up to the task of supporting the added weight. But when done right, you’ll have a beautiful new structure that provides you with the perfect location to entertain, relax and unwind for years to come. And don’t forget to have fun decorating your pergola!

OZCO Building Products hardware was my savior during the building of my project, with their beautiful, stylish hardware that is also heavily galvanized and tough as nails (tougher, actually). And if you’re getting ready to build a new pergola, you may find some useful project plans and supply lists in OZCO’s collection of DIY project plans. These plans come with step-by-step directions, which are great if you don’t have tons of experience with DIY building projects. And if you encounter any challenges during your project, you can contact their knowledgeable team for advice. They’ll help you with any issues, maybe even with getting your wife to stop giving you “that look.”