5 Clever Tips for Designing a Pergola Attached to a Deck

Katy Willis
Written by Katy Willis
Updated April 26, 2022
A beautiful farmhouse with an attached to the deck pergola
Photo: Iriana Shiyan / Adobe Stock

Deck out your deck with some shade

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Adding a pergola to your deck creates a nice, shady for you to enjoy your outdoor living space while avoiding direct sunlight. Growing plants up the pergola's framework adds more shade as well as the alluring scent of the plants you chose and attracts pollinators to your yard. But the key to building a pergola attached to a deck lies in the design. You need a pergola to be safe, strong, and long-lasting. These tips help you achieve just that.

1. Choose Quality Pergola Materials

The quality of your materials is critical when it comes to building a safe, long-lasting pergola that looks good. Mounted on the deck, a pergola has exposed hardware, and the support posts hold the entire weight of the pergola, so strength and durability are vital. 

While there are many options for the structure, pressure-treated pine, cedar, or vinyl are the best options. 

Pressure-Treated Pine

Pressure-treated pine is budget-friendly and undergoes a process that makes it less attractive to bugs than many other woods and also resists rot and mold. However, of the three options here, pressure-treated pine is still most likely to rot or succumb to mold or fungus than the others. You can paint or stain it for a more refined look, or leave it bare for a rustic style. If you do stain or paint it, you'll need to reapply the product every year or two.

Cedar

Cedar is a popular choice as it's fairly affordable and has a distinctive, attractive look and scent. It's naturally resistant to rot, mold, and insects and has a beautiful red hue. However, that lovely coloring fades over time, so you'll need to stain it every couple of years, or it'll fade to a light-medium gray. While more expensive than pressure treated pine, cedar is more robust and has a more refined look.

Vinyl

High-quality vinyl costs a bit more but, unless you're set on a wooden pergola, it's the best option for durability and ease of maintenance. Vinyl is impervious to mold, insects (including termites), and rot. Plus, it doesn't need any painting or staining, as it doesn't fade in sunlight. Vinyl is sturdy and durable, but is the most costly option compared to wood. If you like the look of wood but want the durability of vinyl, you can get wood-look vinyl that closely mimics the look of real wood grain.

Hardware

Hardware needs to be tough to support the posts and roof. But it'll mostly be exposed, so it needs to look nice, too. Post bases and timber bolts made of hot-dipped galvanized steel with a powder-coated finish are the best choice. While more expensive than plain silver galvanized steel, this type of hardware has a superior finish, and looks just like cast iron. Plus, galvanized steel is super strong and comparatively lightweight, making it a solid, reliable option for pergola hardware.

2. Add Railings for Strength

Adding railings between the support posts gives the whole structure strength, even if you use fairly short ones. Plus it adds another dimension in terms of aesthetics. You can also opt for a trellis design, creating a kind of privacy screen while adding strength and stability, and giving you a place to grow climbing plants like honeysuckle. 

3. Use a Lightweight Roof

A luxurious deck with a gray sofa and a pergola providing shade
Photo: Photographee.eu / Adobe Stock

Opt for a lightweight roof. Choosing a heavy roof adds a lot of weight and pressure to the support posts and hardware and destabilizes the structure. Vinyl is a good, lightweight option, as is a nice open trellis, louvered aluminum or vinyl slats, or fabric panels. You can also choose retractable coverings or an awning that you only use in wet weather or when you need additional shade.

4. Attach the Pergola Support Posts to the Deck Joists

For safety, it's crucial you bolt the support posts of the pergola to the joists of the deck, not the deck boards. The deck boards simply don't have the strength to safely hold a pergola and, in strong winds, or just over time, the deck boards can lift, which would cause the pergola to collapse. So save yourself money, hassle, and the risk of serious injury by only attaching your pergola to your deck's joists, just like hanging something heavy on your interior walls, where you need to find the studs to secure it.

5. Hire a Professional Contractor

The safest way to build a pergola is to hire a local general contractor to do it for you. These pros know how to safely build a pergola and can accommodate your design needs and current deck setup. They'll work with you to create a pergola that looks good, is safe, and will last for years. Yes, the cost to build a pergola yourself is less than the cost of hiring a pro, but, unless you have some serious DIY skills, the results from a professional build will be much better—and last longer.

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