Installing concrete anchors on large, existing pergola?

[biosurfer1]

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:




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!

[hcoles]

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

[hcoles]

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

[biosurfer1]

Originally Posted by hcoles

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

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)

[biosurfer1]

Originally Posted by hcoles

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

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

[hcoles]

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.

[cabmandone]

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=CjwKCAjw1JeJBhB9EiwAV612y07G7IBOsKBmiOJe5bxT hqyEN1oc4_wyl9OjnmBxmvcnYtku0b7r1xoC-MQQAvD_BwE&gclsrc=aw.ds

[hcoles]

Expandable anchor sounds good also, maybe stronger.

[cabmandone]

Originally Posted by hcoles

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.

[biosurfer1]

Originally Posted by cabmando

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=CjwKCAjw1JeJBhB9EiwAV612y07G7IBOsKBmiOJe5bxT hqyEN1oc4_wyl9OjnmBxmvcnYtku0b7r1xoC-MQQAvD_BwE&gclsrc=aw.ds

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!

[cabmandone]

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

[stomachmonkey]

Originally Posted by cabmando

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=CjwKCAjw1JeJBhB9EiwAV612y07G7IBOsKBmiOJe5bxT hqyEN1oc4_wyl9OjnmBxmvcnYtku0b7r1xoC-MQQAvD_BwE&gclsrc=aw.ds

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?

[javadog]

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.

[cabmandone]

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.

[hcoles]

Originally Posted by javadog

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.

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

[hcoles]

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

[908/930]

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

[1990C4S]

Wedge anchors are dead simple, cheap, and strong.

[70SATMan]

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.

[biosurfer1]

Originally Posted by stomachmonkey

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

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

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.