Understanding how to anchor a pergola to the ground is an important first step to building your structure.
It's imperative that you properly anchor your pergola to protect your family and your property.
No matter how heavy your structure is, it's top heavy and can easily blow away should you encounter strong winds or a storm.
Let's dive deeper.
Anchoring a Pergola to the Ground
There are several methods for anchoring a pergola to the ground. The method you choose will largely depend on the type of surface you're working with and the amount of effort you wish to put in. No matter which you choose, you need to clearly understand the process to make sure your efforts pay off.
Pergola Anchoring Resources To Consider
Here is a curated list of posts to help you learn more and to help anchor your pergola to the ground.
This is a mixture of our own posts and some recommended reading from relevant external sites.
Lets get stuck in.
In the Ground
If you're installing your pergola over open ground, you have a few options for anchoring it.
For permanent placement, you'll want to dig holes, add posts, and fill with concrete. For this method, you'll start by digging a hole that's 1 foot wide and a depth that's equal to roughly one-third the height of your post. So if you have a 12-foot tall post, you'll dig a hole that's 4 feet deep.
If you live in an area that sees cold weather, you may need to dig the hole deeper to get below the frost line. It's important to get below this line because the freezing and thawing of the ground will unsettle posts that are buried above it.
Once you've dug your hole, pour some wet concrete into it. Insert the post, and continue filling with concrete while using a level to make sure your post is both square and plumb. Continue the process for all posts, and then continue construction of your pergola.
If you're looking for a less-intensive method of anchoring your pergola to the ground, you can use ground anchors. These large, screw-like devices are driven into the ground and the post of your pergola is attached to a bracket at the end of the anchor. This option is a good one for smaller or lightweight pergolas. If you've got a large structure or have installed a cover that could get caught in the wind, it's a much better idea to follow the concrete method described above.
To a Concrete Footing
An alternative to burying your posts in concrete is to create a concrete footing. Like the previous method, you'll dig a hole and ultimately fill it with concrete. However, instead of inserting the pergola poles into the wet concrete, you'll insert an anchor. Once the concrete is set, you can secure your pergola poles to the anchor using a bracket.
To a Poured Concrete Patio
If you already have a concrete patio, you can purchase anchors to attach your pergola to this existing pad.
After determining where the posts will be placed, use a drill to create a hole at the center of where the first anchor will be placed. Clear the dust, and then use a ratchet to attach the anchor and tighten it. The anchor is sufficiently tightened when there is absolutely no play when you try to move or wiggle it.
Repeat the process for all posts, and then you're ready to attach your posts and continue with construction of your pergola.
To a Deck
If you're building your pergola atop a wood deck, you may worry that the deck may not have sufficient strength to anchor the pergola. However, this is rarely a problem, even if you aren't securing the pergola to a beam.
As suggested, you should try to anchor your pergola to one of the deck's beams. It will provide the most support and strength. If this is not possible, you can modify deck boards for safe installation. In this case, you'll attach a 2x6 under the deck boards so that it runs across several boards. Doing this spreads the lift load across a larger surface, creating a more secure anchor point. Once you've done this, you'll secure the pergola posts to the deck using 90-degree strap brackets. These are attached to the deck using wood screws.
Now that you know various ways to safely anchor a pergola to the ground, it's time to continue with your construction project. If you're in doubt about any of the methods described here or don't feel you have the skills to safely complete the job, don't hesitate to call in a professional for some help.
Do I have to anchor a pergola?
To prevent a pergola from blowing away in bad weather or warping with time, it's highly recommended that you anchor it to the ground. Anchoring a pergola will help your structure last longer, but it will also protect your family and neighbors should you experience high winds.
Can I anchor an existing pergola?
It can be difficult to anchor an existing pergola, but it's not always impossible. The toughest part of anchoring an existing structure is lifting the pergola to attach the posts to anchors. Depending on the size and weight of the pergola, you may be able to accomplish the job of lifting it by inviting some friends over. However, if the pergola is especially heavy or large, your only choice may be to call in heavy machinery to help lift it.
What's the easiest way to build a pergola?
The easiest way to build a pergola is to purchase a ready-made kit. A pergola kit will contain all the materials to construct your structure. Some even include the materials to anchor your pergola to the ground. If you find a kit that doesn't, you can easily find the pieces you need at a hardware store. As far as assembling the pergola itself, as long as you can follow directions, you shouldn't have any trouble putting one together. Just remember: building a pergola requires at least two people, so be sure to find a partner before starting.
How To Install Pergola Posts on Concrete
Our friends at Average Joe's Pergola Depot put together a video guide on what is entailed in installing pergola posts on concrete. This will give you a rough illustration of what will be required for your own project. Let us know what you think!