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.

Lighting

Our Favorite Outdoor Deck Lighting Ideas

Illuminate the night with our deck lighting ideas for your outdoor space, from string and solar lights to pool lighting. Find inspiration at Decks.com.

Water Drainage Systems

Best Under Deck Drainage Systems Reviews

An under deck drainage system creates a dry space under your deck and protects your substructure from moisture. Read our review of the best under deck drainage systems 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.

How to Design a Deck

Deck & Patio Landscaping Ideas

Looking for landscaping inspiration and ideas? Check out our ideas for turning your patio or deck into a beautiful oasis for entertaining and relaxing.

How to Design a Deck

Deck Railing Designs

Learn about the newest and most stylish deck railings on the market. Browse pictures of wood, metal, glass, composite and cable rail systems.

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.

Building

Covered Deck Costs

Interested in a covered deck but asking yourself how much it costs? Learn the cost to build a covered deck depending on types of deck covers and add-ons.

Benches, Planters & Skirting

Deck Bench Ideas

Whether built-in or stand alone, deck benches are an excellent seating option. Get ideas and inspiration for your deck bench design with 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

The Ultimate Guide to Mood Lighting for Your Outdoor Space

Light up your outdoor space with effective mood lighting. Our guide covers everything from installation tips to choosing the best lights for a cozy, inviting atmosphere on your deck.

How to Design a Deck

Selecting The Best Composite Decking Color For Your Home

There are many composite decking color options. How do you select the right one for you?

Get more helpful resources delivered right to your inbox

Explore Articles by Topic