Loading

How to Build a Pergola on a Deck

A pergola is a structure built to provide overhead shade. It is usually supported on four sides by vertical posts that hold in place a lattice of wooden members. Some pergolas are attached to the house at one side with a ledger board. If you plan to do this, make sure you take all the same precautions to maintain a watertight connection using flashing and caulking. The sizes of the overhead members can vary, but the lowest boards in the assembly will be the heaviest. Beams attached to posts will support one or more layers of cross members. The spacing and size of these members or louvers will dictate the amount of sunlight that is allowed to penetrate and the visual mass of the structure. Sometimes vines are trained to grow through the latticework to provide a lush natural canopy. 

Pergolas and other overhead structures are subject to building codes. While intended only for shade, these structures often support hanging swings. Depending on the design, slats overhead intended for shade may be close enough to support bridging snow. Due to the structure of some snowflakes, snow is able to bridge over gaps as big as 4 inches or more. Snow piling up on a pergola likens it to that of a roof. Even without snow bridging possibilities, many building authorities will assign a minimum 20 psf live load for the structure to support. 

It is very important to properly attach pergola posts when installing a pergola over a deck. The main concern is how the structure will react under high wind conditions. Most deck builders bolt pergola support posts to the frame of the deck using (2) 1/2" x 6" lag screws with washers per post. This technique is the same as attaching a rail post. Pergolas are top heavy. Without lateral bracing, they can sway in the wind and experience strong uplift forces as the pergola acts as a sail. Attaching sections of rail in between pergola posts will strengthen the pergola. Installing 45-degree bracing in between the post and header beam also will increase stability. Using 6x6s for support posts will further strengthen the structure.

Pergola
PinterestSave
Pergola

Here is an example of a shade pergola built over a deck.


Popular Features Articles
Benches, Planters & Skirting

Deck Skirting and Fascia

Skirting can be an attractive feature that can be added to any low-level deck.

Outdoor Ideas

9 Best Deck Furniture Ideas & Designs

Make your deck the place to be this year. Find unique outdoor furniture ideas for decks of all sizes and transform your backyard into an outdoor living room.

Fencing

Composite Fencing: Reviews & DIY Installation Overview

Are you considering installing a composite fence? Learn more about composite fencing, as well as how to install a composite fence yourself, at Decks.com.

Next Step: Design Articles
How to Design a Deck

10 Tips For Designing A Great Deck

This is an introduction to design. Start here to get some fresh ideas before designing your dream deck this year.

Pool Decks

From Swim to Sun: 5 Tips for Building a Deck Around Your In-Ground Pool

The pool-deck combo is the perfect outdoor layout for a relaxing, warm-weather hang. Check out these tips on how to design your space.

How to Design a Deck

Porch Roof Options

Learn more about designing a deck with a porch roof.

Get more helpful resources delivered right to your inbox

Explore Articles by Topic

Popular Features Articles
Benches, Planters & Skirting

Deck Skirting Ideas

Deck skirting offers more than aesthetics. From added storage to critter deterrence and concealing structures, explore our top ideas for your backyard's transformation.

Arbors & Pergolas

15 Pergola Ideas to Create a Backyard Oasis

Pergolas can add style and shade to your backyard. Get inspired on how to create a backyard oasis with these pergola design ideas.

Outdoor Ideas

7 Outdoor Storage Ideas & Tips

Free up valuable space in your home with outdoor storage options. Find unique ideas for outdoor storage as well as some tips for organizing at Decks.com.

Next Step: Design Articles
How to Design a Deck

10 Fence Ideas to Add Privacy and Style to Your Yard

10 Fence Ideas to Add Privacy and Style to Your Yard

How to Design a Deck

10 Tips For Designing A Great Deck

This is an introduction to design. Start here to get some fresh ideas before designing your dream deck this year.

How to Design a Deck

Deck Design Styles

Learn how to design a deck to match your sense of style and to compliment your house.

Get more helpful resources delivered right to your inbox

Explore Articles by Topic