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Can My Deck Support A Pergola?

Can My Deck Support A Pergola?

With summer weather just around the corner, who doesn’t want to spend some time outside in the fresh air, especially while we are all still under varying degrees of lockdown. 

At times like these, it is nice to crack open a cold drink and sit in the shade of some form of deck cover or another. Some people may even want something as sophisticated as a pergola to protect them from the sun. 

You might ask, “can my deck support a pergola”? The answer is not as simple as many people would like, so let’s break it down and determine if it’s right for you.

What Kind of Deck Can Support a Pergola?

Now we get to the question at hand: can your deck support a pergola? It most likely can.

In fact, few situations render a pergola impossible, but I’ll get to those in a moment. First, let’s talk about your best options depending on what type of deck that you have!

Traditional Wood Decks

The traditional deck arrangement is usually slightly raised to be level with your back doors. In this case, you should be able to attach a pergola to your roof and the existing deck. 

Since not all decks were built equal, it helps to note that the ideal deck for a pergola is low to the ground and relatively sturdy by itself. A low wooden deck with ample support from beneath works best and usually requires little work prior to installation. 

In some cases, the corner beams of the deck can just be dug out and replaced with the vertical beams of the pergola.

If that’s not possible, it is easy for a contractor to cut out square holes in the existing boards of a deck and sink the foundations for the pergola’s vertical support beams where they will be best suited. 

Note that you may want to hire a contractor to build a pergola for you. They will almost definitely build up your existing deck to the level of support it needs to handle the weight of a pergola for many years. 

Concrete or Stone Decks

Concrete or stone decks or patios are absolutely sturdy enough to support a pergola!

Keep in mind that this section may also apply if you built a wooden deck over a cement or stone slab. Though you may have to cut into the wood deck, the support from the stone beneath could help your cause.

There are two primary ways to attach a pergola to an existing concrete or stone patio.

  • First, a contractor must cut through the concrete to sink the support beams into it.
  • Alternatively, you could choose to avoid cutting the concrete by opting for a more extensive pergola with support beams outside of the patio’s perimeter.

You should note that, unless you plan to cut concrete, building a pergola over a simple square cement deck attached to the house’s foundation is about as simplistic as the job gets.

It is so easy that you may not need a contractor if you have a bit of building savvy. If you choose to do a DIY pergola, make sure you plan out the process before starting to avoid any surprises. 

What About Free-Standing Pergolas?

If you simply want some shade without all of the stress about size, weight, supports, and structure compatibility, you may want to consider a free-standing pergola.

Some of these structures can be temporary so that you can store them during the off-season to extend their life. Others take on a life of their own as an independent fixture that extends your outdoor living space, like a tiki bar!

There are two big reasons to choose a free-standing pergola. You can put them anywhere in your yard as long as it’s up to code, and you may not have to worry about support if you aren’t adding the weight to your deck or patio.

What Kind of Deck Cannot Support a Pergola?

There honestly aren’t that many decks or patios that you cannot build a pergola over at all, but there are some situations that make it much more challenging than others.

While it’s possible to install a pergola, you may need to hire an experienced contractor and team to do it safely.

#1 Elevated Patios with Tall Supports

If a patio is elevated off the ground on tall support beams, like a beach house on stilts, it will be difficult to add a pergola to an existing build.

The problem is that the house relies too heavily on the wooden support beams for them to be replaced with supports for the pergola, and you cannot add more weight to the vertical supports holding up the beams.

In these circumstances, exceedingly tall beams of wood would need to be fastened to the outside of existing beams and sunk into the same foundation. It’s possible to do this, but it would be costly and may not be safe depending on how tall the deck is.

Unfortunately, free-standing pergolas also are not an option here. Due to the weight of their bases, they are too heavy to be placed on top of most stilted decks safely.

#2 Decks Built Over Water

Some forms of decks built over bodies of water have a similar issue as elevated patios.

The amount of work it would take for a contractor to sink permanent foundations into something like a lake bed or beachfront would require so much time and money that it would not make much sense.

That said, some bodies of water are shallow enough that you can install free-standing pergolas on top of the sand or lake bed. However, be aware that the water currents could slowly sink the bases deeper over time and may even move the entire structure.

While free-standing pergolas may be a better option, in this case, they aren’t a perfect solution.

In both cases, the deck itself can support a pergola but cannot sustain the stress of the installation process. If you are planning a new deck from the ground up, you or a contractor can undoubtedly find a way to incorporate one into the design.

Tips for Installing a Pergola to an Existing Deck

Strength and stability are the critical factors for adding a pergola to your existing deck or patio.

Unless you’re facing one of the challenging situations noted above, you shouldn’t have too many issues, especially if you follow these tricks!

  • Splurge for pressure-treated wood, at least for the support beams. Choosing wood support beams that can handle anything you throw at it could be your best bet for long-term use.

  • Choose a lightweight roof. The shade is nice, but if you make a top-heavy pergola, it could stress your deck and reduce the lifespan of the entire structure.

  • Consider railings. Crossbars create additional support to make the structure more sound, and they can be safer for everyone who uses the space.

Conclusions about Building Pergolas on Your Deck

Put simply, if there is a will, there’s a way. Most decks can support a pergola in one form or another. Most contractors will be able to draw up a plan to add a beautiful pergola to your already beautiful deck.

Low and simple decks are excellent in supporting a pergola, while stilts are less suitable because they are difficult to add to.

If you want to add a pergola to an existing deck, things can get tricky. But ultimately, any deck can support a pergola if planned as part of the base structure.

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