The How To Guide For Mounting Pergolas To Any Surface
A properly mounted pergola will stay true to shape and safely secured for life. Making sure the posts don’t move over time will give you peace of mind that your investment will stand the test of time.
Even though a pergola is heavy and difficult to move once assembled, it has to be anchored securely to the ground for a number of reasons. Primary among them is safety. A poorly anchored pergola can be moved by high winds if there is a canopy or cover on it as this adds to the wind load the pergola could see in a storm or high winds. Secondary is to ensure long term stability to keep the pergolas shape. Wood over time can bend, bow and twist with the seasons and the frost. With proper anchoring, your pergola will keep its shape for many years.
The following is a review of the different surfaces pergolas mount to and the fastening options for each of them:
Mounting Pergolas to Deck Surfaces
A properly constructed deck provides ample strength to anchor a pergola. However there are a few points to make to ensure you get the most strength you can with a little more effort.
Any pergola post can be anchored to a wood surface with 90 degree strap brackets. There are a few additional considerations before screwing into the post and into the deck. First, be sure you are screwing into the deck’s beams, not the deck’s boards. If a beam is not located where you want a post, put a 2X6 flat under the deck boards such that it runs across a number of deck boards. Then screw through the deck boards into the 2X6 underneath. This spreads any lift loads over a number of boards instead of one. Using the deck posts/railings as anchors are recommended because they go right down to the footings or the sub structure. Please make sure that the screws used are long enough to reach the support beams underneath.
Mounting Pergolas to Poured Concrete Patio
Hammer set fasteners for concrete are easy to set and are very strong. It is important to ensure the poured concrete is of sufficient mass to be used with these fasteners. Most contractors like to see 6” of depth to use this method. If you are going to pour a concrete pad for your patio, make sure you specify 6” depth of pour. With that in place, anchoring is a simple matter of hammer drilling the holes for the fasteners, hammering the fasteners into place, and bolting down the mounting brackets for the pergola posts.
Mounting Pergolas to Paving Stone Patio
These are the most troublesome and frustrating surfaces to mount to. Although tempting to take an easy route, you should not fasten posts to paving stones. Paving stones do not provide sufficient anchorage for a pergola that will be subject to wind loads and the seasonal forces that will move the structure over time. You have to remove the stones where the posts are located and sink footings according to your local code. In the northeast, that is typically 48” to a concrete poured footing. There are other footing options we will discuss (helical screws, earthen screw, etc) but in any event, a footing is needed to mount properly to paving stone surfaces. Note that the image above represents the footing that should be used under the paving stones.
Mounting Pergolas to Ground ‘Foundation’ Anchoring
Previously, you would dig a hole for each post and pour a concrete footing at the bottom of each hole for each post to ‘set’ in. Once the concrete had set, you would build the pergola on the posts. Today, there are more efficient options to set footings such as helical piers or footings. If you are a do it yourselfer, the helical pier may be a bit difficult to set because equipment is needed to drill down to the 48” depth most require for code compliance. However, your contractor can screw these piles right into the ground with an auger type attachment on their backhoe. The only caution is if there is a potential for construction debris like old bricks and wood to be buried.
Mounting Pergolas to Ground ‘Location’ Anchoring
Similar to the helical pier but with much less strength is the earthen screw. If your pergola is sitting on ground and you want to be sure it does not blow away, these can do the job of securing to the posts into the ground. However, they will not be part of a proper foundation like a helical pier or poured concrete footing. The same goes for steel pole anchors. They provide lateral location for posts but do not prevent frost motions or anchor from negative wind (lift) loads. If your pergola has a canopy or cover on it, stick to the foundation type anchors.
When mounting a pergola, be sure to follow these tips to enjoy a lifetime of security in knowing your pergola is safe, secure, and reliably fixed to keep its shape.
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Any idea where I might buy the earthen screws, as pictured in the section “Mounting pergolas to ground “location” anchoring”? Would these work for securing an arbor?
Home Depot has them o their site as “No-Dig Ground Screw.” You may need to order some for delivery to your home or the store.
We bought a house that already had a 11×12 pergola on place but was not anchored. What options do we have other than taking the entire thing down and starting over?
Hello Michael, anchor ties can be added to the bottom of posts. The challenge will be safely picking the pergola up to and add the anchors. Multiple people, or a hoist may be required, depending on the weight of the pergola. Hope this helps!
We have a patio tiled w marble, over base and gravel.
What would be the best method to anchor our posts (6 x 6).
Must we have a footer ?
Hi Gary! Yes, footers are generally recommended when anchoring any type of structure posts, regardless of weight and/or size. Review your local building code standards to ensure you’re in compliance.
Can you elaborate on how you would attach the pergola to wood using the 90 brackets? How would you add the 2×6’s ?
Planing to pore 16 × 30 ft patio do I need still footings for a pergola that I am planing to built on top of the patio and if yes what kind of footings do I need?
What are the dimensions for the ground augers?
I am looking to put the auger inside a 3″ ID pipe. Screw it into the lake bottom
everyone must love reading this
Thanks for the post on how to mounting pergolas to any surface! My wife and I are looking to upgrade our patio area before we sell the home and this is something that we needed! We have no idea that you could anchor them into the ground like that. Thanks for the information!
Thanks for the helpful posts. I have run into the problem of having to set 4×4’s for a pergola I will build.
The ground in most areas is shallow soil over shale and other rock ledges. The area chosen is flat but the underlying rock makes it very daunting to dig, if not impossible without heavy equipment. I am considering drilling holes and using rod to anchor steel 4×4 mounts. However, I am still nervous about how strong and effective that effort will result. Cost effectiveness would be a major consideration. I’m not building a bridge!
Thanks in Advance
I am building a deck, more like a platform. It will be made of 2X12 rafters and perimeter framing regular wood deck boards and it would lay, unattached, on a existing bed of gravel. Can I go through the boards, down 12″ and install the posts to the deck that way? I would add plenty of blocking and cross bracing for attaching the post – the planned platform would be no less than 20×50
I need some help. Can i use ground screws (titan deck foot auger and anchor) to anchor my pergola? I’m worried the screws won’t be stable enough. The pergola won’t have a cover or canopy. Just 2×2 slats so wind shear shouldn’t be a problem.
Dimensions are
6 Vertical Posts – 6 x 6 x 10
Wide and Horizontal posts on top will also be 6 x 6’s.
Looking for other options other then pouring a concrete base.
We want to attach 6 x 6 pressure-treated posts to brick piers (or columns) on one side of a pergola, and on the other side, directly to the wooden deck. How would you recommend attaching the posts to the piers?
Typically, an anchor plate or post base hanger would be used to attach a post to a column. The plate/hanger require a solid base, so the pier column cannot be hollow. We recommend you contact an independent contractor in your area to conduct a site visit to properly assess the need.
Any ground screw recommended? I searched in Lowes but only mail box post for a 4′ * 4 lumber’, I have concern that it wouldn’t be strong enough for a 10 * 10 pergola.
Hi Bella,
Try sourcing Pylex Foundation Screws. Lowes, and Home Depot should hold supply. They can support up 5,000 pounds per screw.
Hope this helps.
Is there anyway I can secure my canopy to my treated deck so it’s permanent? The canopy is structured for ground so it would be a 2 part job?
Hi Carolyn,
Yes most structures can be anchored to an existing deck. Anchor your post to the deck joists, not the deck boards.
Good luck!
Any advice on attaching to paver stones? Can I drill in between the stones, and anchor there, I think there’s a bit of space between the pavers.
Hi Stephen,
It would depend on the size, thickness and weight of the paver stone. Smaller pavers may crack when drilling into them, they also wont provide much support from an anchoring perspective. Larger pavers such as 16″x24″x3″ may be suitable, but consider pull away strength on the anchors used, a strong updraft could pull the structure from the stone or displace the structure and stones. Usually a safe bet to anchor to concrete footings or the frame of a deck.
Hope this helps.
Just for clarification – would the wood posts sit on top of the pavers with the anchors going through into the footing? Or the posts sitting directly on the footing with the pavers cut around the post?
Hey mike did you ever get an answer to your question…im doing the same project. Thanks
Hi Mike and Ryan! Apologies for not seeing this post sooner. Best practise would be to anchor the post directly on top of the footing and cut the pavers around the post. Hope that helps.
It’s a great source of knowledge; I think it will be helpful for lot of people who are looking for learning more about mounting pergolas guide . Thank you very much for sharing this article.
I have a steel 10×14 pergola it will be used without a fabric canopy. The weight is 500lbs will this still require concrete footings on a brick paver patio? What other options are there for mounting?
Depends on the weather elements such as wind speed/force in the area. Generally speaking a heavy, open frame pergola requires little anchorage, but the supplier should be able to provide the proper guidance.
Can you bury 16x8x8 concrete block vertically and and anchor the pergola posts to four of these?
Concrete footings are common practise. Weight of the footings are an important consideration.
Hey Ted
What about anchoring a 12x 24 6 post pergola to asphalt?
Hi Michael, Masonry/Concrete anchors can be considered, however if the ashphalt is profile is thin it may give way over time.
Hello, Ted,
My cedar wood pergola kit has tri-poled corners (symmetrical L-shaped / (3) 4x4s / with 4 vertical wood cross brackets between each post, or 8 cross brackets per corner), and seems very stable without being anchored. The construction guy, I purchased it from, had the model sitting on deck blocks (3 per corner) above the ground. I need to raise the pergola, as I will eventually build a deck around it, so that the deck does not have to support the pergola. Unfortunately, the pergola has short legs (due to the X brackets) and therefore cannot be sunk into the ground, but sits nicely in the deck blocks (3 per corner). I found square deck blocks that can be stacked and therefore cemented or bracketed together. If I can anchor the pergola in the deck blocks, and anchor the deck blocks into the established ground (via rebar or Oz anchors), do you think I need to have below-ground supports? It will sit in a niche corner of my home, protected by two walls, and will not be attached. I would never ask this question with single-pole corners, but I have triple-duty corners that can literally stand by themselves. Thank you for your time 🙂
Hi Kat,
Unfortunately, we’re not familiar with the pergola design you’ve queried. We recommend you ask the contractor whom you purchased the structure from.