Installing concrete anchors on large, existing pergola?
 

I have an existing pergola on my property sitting on concrete that does not have existing concrete anchors holding it down, even though there are post brackets there (No idea why they are missing)

The post brackets look similar to these:
http://forums.pelicanparts.com/uploa...1629912568.jpg



My question is being so large, I can't see a way to move each post out of the way to hammer drill the holes for the concrete anchors, so is there a way to just drill the holes through the post bracket holes? Or do all anchor holes need to be bigger than the bracket holes?

I've only looked at a couple concrete anchors but all of them were a larger diameter than the bracket hole, so I figured that was a no go...looking for suggestions. Thanks!

Idea:
1 - unbolt existing structure and move it over 1 foot in any direction
2 - using a hammer drill - drill correct size hole for ? 3/8" concrete bolts, remember to clean out the holes very well using compressed air (you can use one of those air cans from HD). The compressed air cans come with a straw that allows getting to the bottom of the hole and forcing the dust out, you can also use another object to help get all the dust out along with the compressed air.
3 - move structure back while installing the new brackets
4 - install the concrete bolts/screws

e.g. Screws - Tapcon 3/8" x 3"

That was my plan, but moving it a foot out of the way could be troublesome. It's blocked on 3 sides by concrete stairs/built in planters and a iron fence. The bigger issue is this damn thing is heavy and the posts barely move independently of each other (otherwise I would treat it like a 6 legged dog, slowly moving each post one at a time)

That is my plan B, but I have some concerns that concrete screws can handle that kind of load (though it's better than the nothing that's currently holding it down)

It would be 24 screws holding it down (4 per post x 6 posts) so maybe i'm over thinking this. We get windy here but no hurricanes/etc

ah, okay. Maybe try jacking the whole thing up one post at a time until it is high enough? That could be troublesome.
Another idea, maybe not a good one, cut off each leg and insert new leg piece with new bracket that matches the cut off length. Then put a gusset, of some sort, across the cut line.

I'm not followin ya. You should be able to buy an expandable anchor that will fit the hole size you decide to go with. So if you want to use a 3/8 anchor, you drill the appropriate hole, drive the anchor in the hole, then put the nut on and tighten to the spec necessary to set the anchor.

I'm talking about an anchor like this only not necessarily that size.
https://www.grainger.com/product/15X102?ef_id=CjwKCAjw1JeJBhB9EiwAV612y07G7IBOsKBmi OJe5bxThqyEN1oc4_wyl9OjnmBxmvcnYtku0b7r1xoC-MQQAvD_BwE:G:s&s_kwcid=AL!2966!3!281698275318!!!g! 470148656870!&gucid=N:N:PS:Paid:GGL:CSM-2295:4P7A1P:20501231&gclid=CjwKCAjw1JeJBhB9EiwAV61 2y07G7IBOsKBmiOJe5bxThqyEN1oc4_wyl9OjnmBxmvcnYtku0 b7r1xoC-MQQAvD_BwE&gclsrc=aw.ds

Expandable anchor sounds good also, maybe stronger.

Yeah. I'd probably put two in each post bracket and call it good. If he really wants to go all out, pop all 4 in but with the right size I think two in each post would be sufficient.

I would have no real issue with a tapcon though. Those things are pretty strong.

That should work great. Don't know why I wasn't finding that earlier. The only ones that were showing up under my search were more like inserts that epoxied in the hole, and all the inserts were a larger diameter than the bracket hole.

Thanks!

That's what we're here for! Glad I could help.

I think the issue is the holes in the plate are smaller than the holes he needs to drill for anchors.

So my thought would be just drill the plate holes larger.

Use a larger washer on the anchor bolt.

But then does the plate need to be sandwiched between the anchor and bolt?

Not a mechanical engineer but logic says if sandwiched the plate helps spread load?

As in if the anchor fails it can still pull through the plate?

Honestly, I'd not be worrying to much about it.

If it's too large and heavy to move without equipment is it really going anywhere?

What value do the anchors provide at that point?

Use a couple brackets like these, one on each side of the post and run a bolt through the post. Try and find some where the holes that are drilled on the bottom leg are far enough out from the post that you can actually get a drill perpendicular to the ground and drill the holes. If you can’t find them, make something just like them.

http://forums.pelicanparts.com/uploa...1629914755.jpg

BTW, are you sure they didn't put an anchor inside the bracket before setting the post? Some brackets have that option. What I mean is, just because the holes outside have nothing in them doesn't mean there isn't something tying the bracket to the concrete.

Those look good or get post anchors with 3 sides or 2 sides. E.g. VITA Bolt Down Bracket System. I found on HD.

I like the A24 Simpson idea. The VITA doesn't have tabs sticking out across the concrete.

I can't tell the diameter of the holes, I find the Simpson site is a pain. A long 3/8 hammer drill bit will get in there easy, and a 3/8 Wedge anchor is good for about 4000lbs in tension when set properly. I just looked they have 3/8 SDS drill bits up to 39", can just stand there and drill. LOL

Wedge anchors are dead simple, cheap, and strong.

Even simpler is drilling the same size holes as the bracket without moving anything and then install all thread using concrete epoxy. No need for anchors and they make concrete epoxy that will take the load. That's one method used to install anchors to house foundations that never had them originally.

PLEASE tell me you have a good argument that will convince my wife of this :D

Using a hammer drill and setting 24 anchors seemed easier than winning that debate against a non-technical, non-engineer person who only envisions it being blown up in the air and landing directly on my son's bedroom.

Got a picture of the thing?

Yeah, got a picture?
Does this pergola have a roof that could act like a giant 'sail' if the wind caught it?
If so, I can see the need/desire to anchor it. Our patio 'cover' is only held down with four bolts total, but it's so 'porous' the wind couldn't lift it if it tried.

I hate drilling concrete. I always seem to hit a piece of aggregate...

James, I use a rotary hammer drill to drill concrete. It goes straight through aggregate. Ryobi - cheap as chips and goes at concrete like a Rottweiler.

It's usually the rebar that gets me torqued.

If you go with wedge anchors and I think they are a good choice for this, make sure they are shorter than the thickness of the concrete, drill the hole much deeper than the length of the anchor (don’t want it to bottom out), get the dust out of the hole, put the washer and nut on the top flush, drive it down as far as it goes then tighten the nut.

Lots of people try and drill a perfect depth then put the anchor in the hole and then add the washer and nut- usually it sits too high and you end up with too many threads above ground.

A good argument and one that would convince a wife are two completely different things and at least one of them is a Unicorn.

Go rent a big fan to put under it pointing up. The say "look honey... it's not budging!" It might work!

Yes, it has a roof. I dont have an exact picture, but it pretty much looks like this:


http://forums.pelicanparts.com/uploa...1629927553.jpg

So I suppose it's technically possible it could lift, but I feel like if it's ever that windy, we will probably have bigger problems to deal with.

That has a fair bit of sail area. Not sure what the sail area to weight ratio would be.

Two anchors each of the corner posts ought to do it; if you want to make it symmetrical two anchors at all six…

I have no idea how the roof structure is connected to the posts, that might be an argument for all six.

I would use half-inch anchors.

I used these exact brackets with a fence that I built and installed on top of a concrete patio.

I recommend using expanding concrete anchors. I used 1/2" x 3" and once the hole is drilled (pain btw) I tapped the anchor into the hole and the posts are not going anywhere.

I like the idea above where you are temporarily moving the pergola. However, that may be easier said than done - especially if it is attached to the house. Maybe you could attach some type of 2x4 to the post and use a floor jack to jack up just enough to get the bracket onto the pergola. Then set it back down and drill your holes.

I did not use anchors for mine and it's as solid as a rock.

Drilling holes with the post bracket in place probably means your holes will be drilled at a angle.



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http://forums.pelicanparts.com/uploa...1629930682.JPG

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The permanent solution.
Here's what I'd use to glue the all-thread into the concrete. I've used it before and if you follow all the instructions, especially regarding getting all the dust out of the holes, this will cure harder than the concrete and grip that thread so hard it'll take an act of congress to remove it. I'll bet two fasteners per post would be plenty, too. (set at the diagonal)

http://forums.pelicanparts.com/uploa...1629934085.jpg

Just out of curiosity, is there a good reason that the original builders didn't install fasteners in the first place? I mean, they might as well have just set the end of the post on the ground....

[QUOTE=herr_oberst;11437022]The permanent solution.
grip that thread so hard it'll take an act of congress to remove it.
/QUOTE]

Good advice, but I didn't use any adhesive because at some point I will be removing mine and do not want to make the job any harder than it already will be.

Using an impact wrench is the way to go, BTW.

http://forums.pelicanparts.com/uploa...1629938781.jpg

Remove Trim highlighted above. Add tie down straps, and replace trim to hide.

Hurricane Sandy, my pergola:

http://forums.pelicanparts.com/uploa...1629938883.JPG

Here’s your answer right here.

Baz even brought red heads to the site!

You bet! :p

https://imagevars.gulfnews.com/2012/...3629_large.jpg

We use one of their products and also Hilti when we dissasemble/move our large antennas from one site to another when the customer wants to re-use a foundation.

We don't mess with anchors, they are not as secure. I've seen wedge anchors pulled out before.

If it works with the wind loading of a 13M antenna reflector,,,,,,:rolleyes: