Can My Deck Support a Pergola

Can My Deck Support a Pergola?

In Lawn & Garden, Tips by Jamie

Knowing the limits on your deck is important, especially when you want to install a big beautiful pergola. Pergolas differ in weights and you may be curious to if you deck can even handle all that weight. Can a deck support a pergola? 

Most decks have the ability to support a pergola. Modern decks are made to be able to hold at least 100 lbs per square foot of decking, pergolas often weigh anywhere from 150 to 500 lbs. Lighter pergolas do not require extra reinforcement while heavy pergolas may need extra deck reinforcement.

In this article, we’ll cover everything you need to consider before installing the pergola. We’ll also explain different kinds of pergolas and their weight as well as additional tips to keep in mind.

Things to Consider Before Placing a Pergola

Before placing a pergola onto your deck, you need to make sure you’re aware of the type of deck or patio you have. You’ll also want to take note of the pergola’s weight and the age and condition that your deck is in.

Let’s talk a little more about each of these important criteria.

Type of Deck or Patio

Whether you have a raised or rooftop deck, or one made of composite right outside of your back door, the type of deck or patio you have will dictate how you install the pergola. Although you can install a pergola onto any deck, it’s easiest to install them on decks that are lower to the ground. Decks that are raised on stilts are trickier to add to as there isn’t as much support.

Weight of the Pergola

The weight of the pergola will vary depending on the material it’s made from. For example, a pergola made from wood or composite is going to weigh far less than one made from reinforced steel.

There are several different kinds of pergolas, so it’s important to make sure you know the specific weight of the one you have. Along with that, you need to know how much weight your deck can hold. 

Age and Condition of the Deck

You should also bear in mind the age and condition of your deck. Depending on what the deck is made out of, the amount of time it takes for the material to break down will vary. For that reason, you may want to rebuild an older deck before installing a pergola. This way, you don’t run the risk of the entire deck collapsing and causing more damage than you’d like to deal with.

Different Types of Pergolas and Their Weight

There are four main types of pergolas: open-top, vinyl, steel, gable, and pergolas. Each type comes with its own unique features, pros, and drawbacks. The type of pergola you decide on should directly stem from the environment in which the pergola will be installed in.

To get a general idea of each type and what they’re best for, check out this chart:

Type of Pergola Weight (lbs) Best for…
Wooden Pergolas 350 lbs or more Optimizing airflow, aesthetics
Steel Pergolas 140 lbs or more Areas with extreme weather, longevity
Vinyl Pergolas 150 lbs or more Extreme temperatures, inclement weather, mold/mildew prevention
Gable Pergolas 500 lbs or more Shelter from non-ideal weather, adequate water runoff

1. Wooden Pergolas

U-MAX Outdoor Pergola 12'x10' Wood Pergola for Patio Deck Garden Gazebo

Wooden pergolas come in a variety of sizes and styles. While some are made with classic latticed roofing, others have an open-roof design with the ability to install a pergola sail. Pergola sails are pieces of fabric that serve as the roof and are good for providing extra shade from the sun.

Wooden pergolas can weigh as little as 350 lbs and as much as 4000 lbs total. The weight of a wooden pergola heavily depends on the size and design you’re looking for.

2. Steel Pergolas

an example of a steel pergola

Steel pergolas are ideal for withstanding inclement weather as well as serving a modern or avant-garde aesthetic. Because steel is an incredibly durable material, it lasts a lot longer than other pergola types. The weight of a steel pergola also varies, but will usually weigh at least 140 lbs.

3. Vinyl Pergolas

DuraTrel Queensbrook Pergola

Vinyl pergolas are another alternative to wood that offer longevity. Vinyl is also naturally water-repelling, so it’s less likely to develop mold or mildew after heavy rain. Not only are vinyl pergolas more long-lasting and durable than wood pergolas, but they’re also less expensive and work perfectly for someone on a budget.

4. Gable Pergolas

When you hear gable pergola, the first thing that should come to mind is the open-shelter house at your nearest park. That open-shelter building is essentially an oversized pergola. While those can weigh upwards of 4000 pounds, small gable pergolas can weigh as little as 500 lbs. This type of pergola is ideal if you want adequate protection from the elements while still spending time outdoors.

Pergola Placement FAQs

Can You Measure the Weight of a Pergola?

To measure your pergola, you’ll need to know the weights of each rafter, as well as the roof (if any). For an oversized pergola, you’ll typically be looking at 1000 lbs per beam. With four beams, you’d be looking at 4000 lbs total without taking into consideration the weight of the roof you choose.

So, let’s say your pergola beams weigh 500 lbs per beam and your standard latticed pergola roof weighs around 300 lbs. When you multiply 500 x 4, you end up with 2000. Now take that 2000 and add the 300 lbs roof to get a grand total of 2300 lbs.

Can My Wooden Deck Support a Pergola?

You can install a pergola on a wooden deck. To do this, though, you’ll need to make sure the base structure of your deck has the correct design to make installation easier. If your deck is already in place, it’s not impossible to install the pergola, you’ll just need to work a little more to install the right base parts.

Can My Composite Deck Support a Pergola?

Installing a pergola on a composite deck is possible as long as you use a ledger board to install. The ledger board is what helps support the beams as you attach them to the roof of your pergola. When installing, make sure to keep in mind the amount of weight your deck can hold per square foot.

Can My Concrete Slab Patio Support a Pergola?

You should be able to install a pergola on your concrete slab patio. However, to do so you must ensure the concrete slab is at least four inches thick and there need to be at least 12 inches of distance between the beams and the outside edge. With concrete slab patios, the structure is held in place by anchor brackets that have been bolted to the concrete.

Can my Pavers Support a Pergola?

Although you technically could install a pergola on top of concrete pavers, it’s not recommended. The pavers aren’t usually strong enough to support the pergola in the event of strong winds. If you choose to install a pergola on a paver patio, you’ll need to add additional weight to each beam to anchor it down.

Can My Rooftop Deck Support a Pergola?

You should be able to support a pergola on a rooftop deck. In fact, this is a great way to display your greenery and other plants in your home. Rooftop decks work just the same as any typical deck, so it should work well as long as the deck can support at least 100 lbs per square foot of space.

Can I Install a Pergola on a Raised Deck?

Although pergolas can be installed on virtually any deck, it isn’t recommended to do so on a raised deck. Decks that are higher off the ground and are held together by support beams have a lower weight tolerance than decks at the ground level. Because of that, it’s not usually stable enough to hold larger pergolas. However, if you want to install a lightweight, small pergola, you should be okay.

If you want that thick and heavy pergola just make sure your deck has been built professionally and the experts ensure a heavy pergola can be installed. 

Can I install a Pergola on a Deck Built Over Water?

Decks built over water are, technically, raised decks. Because of this, you probably shouldn’t take the chance of installing one on the deck if you are unsure of the deck weight capacity. The excessive weight of the pergola could cause the deck to collapse, leading to potential disaster.

Having an expert opinion is recommended when wanting to build a heavy pergola on a deck that is built over water. 

Additional Tips For Pergola Installation

When shopping around for a pergola style, make sure you choose one that fits well with your aesthetic. With that said, you shouldn’t sacrifice practicality for vanity. If you live in an area with harsh weather or excessive humidity, you’re going to want to stay away from wood or other materials that absorb water. These materials are more likely to develop mold.

Along with that, it’s helpful to remember that the square footage of your deck will tell you how much weight it should be able to hold. For every square foot of decking, you should have the ability to hold at least 100 lbs.

You may also choose to spruce up the space by adding some hanging vines or other decors to the pergola walls and roof.

Parting Thoughts

A pergola is a perfect addition to the deck of anyone who wants something a little extra. This landscape addition usually allows up to 300 lbs of extra weight, making it perfect for hanging plants and other decors.

What type of pergola speaks to you the most? We’d love to know!