I am starting to excavate my backyard for a project, and the next step will be to pour concrete footers for a pergola. The pergola uses a bracket system, and the footer in this system has its own holes for attaching to a concrete footer. This is to say, the pergola will be on top of the concrete footers and not set in the concrete. The pergola posts will be 6x6, but really I am dealing with something a little larger as the bracket is 8x8 (11.31 inches diagonal). You can see the product link here.

I have been reading about this online and it seems there are a ton of moving factors here. I will list out the things I am trying to figure out.

1. Some people have said to dig a bare hole and pour concrete into that and other have said to use a Sonotube for the form, and pack in earth around the Sonotube. I think a Sonotube would be easier as that would give me a really clean top to work with.

2. If I use the Sonotube, will a 12" inch one be wide enough? The drill holes in the bracket are 7.5" apart and the bracket itself is 8" wide so I am good there. A 12-inch one also is just wide enough to accommodate the 11.31" diagonal of the bracket. I don't see any forms larger than 12-inches so if I need to go bigger I would have to custom build some out of wood perhaps.

3. I also need to think about proper depth. I live in Austin, Texas where the frost line is about 12-inches. However, I have a lot of clay in my backyard and I have heard I should do 24" inches to give it a better footing as the clay will expand and contract.

4. Is there anything else I am not considering? In short, I just need to pour concrete footings for my pergola. I want to do it myself to save some money but am willing to take the time to do it right.

Thank you very much for reading this and offering any help. I greatly appreciate it!

 

We only allow one thread per topic. This is your thread.

The pros will be by to help you out.

 

All good PJmax . I have had experiences in the past where I posted in the wrong forum by accident, and got no replies which is I did that. I assume you checked out both areas and determined this was the best one?

 

This should be a good forum for your project. If it turns out it's not.... we'll move it for you.

 

You do not state the span, weight or type of ground. Soft wet ground deeper and larger supports
Here in Arizona for a simple back porch they pour 3' x3' x 18" deep for a 4 x 4 post.
Worried about wind lift.

Simpson Strong Tie has concrete to wood products that will not set you back 84 dollars
https://www.amazon.com/Simpson-Stron...141835&sr=8-11
This is what is used here because of termites. Wood can not touch the concrete. If you have plans have they been looked at by the local authorities. Building projects with out permits can create issues when selling the property.

 

Drangd The ground is mostly clay in the back where it is going. The pergola will be 8x10x10. If you see the link I provided, I already have a product for attaching to the footer once it is poured.

I have already checked and I do not need a permit for this structure.

 

Does anyone else have some advice? Thanks.

 

You have an opportunity to save some work here. Imbed j-bolts into the footers to secure the brackets. No drilling needed.

 

Wirepuller38 Interesting! I suppose I would need to make sure they are 100% in the right spot. What is the proper way to make them not stick up a lot? Do I need think about the thickness of the bracket flange and the thickness of the nut in order to make it look it good?

I suppose either way there is risk. If I don't do it this way then I have to make sure my drilled holes are perfect as well.

 

I pull strings marking the post or anchor bolt locations before pouring the concrete. Then the strings are there so you can accurately locate the anchor bolts in the pour. The post brackets have some room for making final adjustments.

I don't worry too much about how much bolt is protruding from the pour. After the brackets are installed I cut off the excess with a reciprocating saw or grinder.

 

The product description says that the holes are oversized. That will give you a small amount of wiggle room but your anchor bolts will have to be very close to the support holes locations. You should make a template of the support base, install the bolts in it and rest it on top of the sonotube when the concrete is poured. Remove the nuts and template after the concrete has set. Since the holes are oversized you should use a washer then the nut. Once they are tightened down, cut the protruding bolt off at the top of the nut.

If you look at the Simpson support you can see that it has a single elongated hole in the center to allow for final positioning.

 

Pilot Dane 2john02458 Those are great ideas, thanks! I did not even think about grinding off the excess, and a template makes perfect sense.

Do you have any thoughts on how deep I should install these in the Texas climate? My backyard is def mostly clay. The frost line is only 12-inches though.

One other thing I am trying to figure out is how to put the flagstone patio around the Sonotube and brackets. I suppose I could have the bottom 2-inches of the bracket not be available/showing as that could meet up with the 2" flagstone, ands have black rock or limestone screenings between the flagstone and bracket. I am just trying to get around not having any of the concrete showing. I suppose this would cover the j-bolts too. I hope this last part made sense.

 

Wirepuller38 How long (inches) of a J-bolt should I be using for this purpose? I guess I should also ask, how much of that length should be buried in the concrete? Thank you.

 

Follow the instructions for your brackets.

You could use two nuts to temporarily attach the bolts to the brackets before inserting the bolts into the wet concrete. This would resolve the spacing issue and allow the bolts to be plumbed by leveling the brackets.

 

Wirepuller38 That's genius, and I love it. Thanks so much!