# How to install posts in concrete



## preciouschristy (Jun 14, 2009)

Hi all-
I'm building a pergola on an existing concrete slab. I'm using 4x4's, and I'm trying to find the best way to attach them to the concrete. I bought some Simpson Strongtie ABA44 post bases, are they as good as the AB44? Although the ABs been discontinued, I know a place I can get them, but are they better than the ABAs?

Also, the plans I have (from Popular Mechanics) say to use Tapcon screws, but the post base info says to use only 1/2" hot-dipped galvanized anchors. I don't want my pergola to fall down, so I want to use the right thing. I do have a hammer drill, and I've used the Tapcons before (in a different project), and I thought they worked pretty well, I'm just not sure they're the best to hold up an entire pergola. If I need to install a 1/2" anchor, what size hammer-drill bit should I use?

Thanks


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## cortell (Nov 27, 2010)

preciouschristy said:


> Hi all-
> I'm building a pergola on an existing concrete slab. I'm using 4x4's, and I'm trying to find the best way to attach them to the concrete. I bought some Simpson Strongtie ABA44 post bases, are they as good as the AB44? Although the ABs been discontinued, I know a place I can get them, but are they better than the ABAs?
> 
> Also, the plans I have (from Popular Mechanics) say to use Tapcon screws, but the post base info says to use only 1/2" hot-dipped galvanized anchors. I don't want my pergola to fall down, so I want to use the right thing. I do have a hammer drill, and I've used the Tapcons before (in a different project), and I thought they worked pretty well, I'm just not sure they're the best to hold up an entire pergola. If I need to install a 1/2" anchor, what size hammer-drill bit should I use?
> ...


Wow. I'd like to see that PM article. Tapcon screws for a post base connector? Maybe just Elmer's glue would work :whistling2: There's several ways to skin that cat--expansion bolt or epoxy. Depends on preference. Sounds like you're going with expansion bolt. You need to read the instructions that come with the bolt; it'll tell you what size hole to drill.


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## preciouschristy (Jun 14, 2009)

The PM article is here: http://www.popularmechanics.com/home/how-to-plans/pergola/3352816
Other than the Tapcon screws, the plans seem fairly decent.

I haven't decided what to go with yet, that's part of what I'm looking for here. I haven't done this before- so what are the pros and cons with epoxy vs. expansion bolt? It sounds to me like epoxy would form a stronger bond (since that's kind of what epoxy is for)- but what would you (or anyone else) recommend?


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## cortell (Nov 27, 2010)

preciouschristy said:


> The PM article is here: http://www.popularmechanics.com/home/how-to-plans/pergola/3352816
> Other than the Tapcon screws, the plans seem fairly decent.


Scary. I'd never rely on Tapcon screws to tie down a heavy column that is holding up a lot of lumber over my head. Then again, I just saw a cable show yesterday where surface wood mold was treated by spraying a mixture of water and bleach, even though experts have been screaming for years NOT to treat mold that way. 



> I haven't decided what to go with yet, that's part of what I'm looking for here. I haven't done this before- so what are the pros and cons with epoxy vs. expansion bolt? It sounds to me like epoxy would form a stronger bond (since that's kind of what epoxy is for)- but what would you (or anyone else) recommend?


Epoxy is indeed stronger, but trickier to install. In order for it to work well, it has to be mixed precisely, the hole must be cleaned thoroughly, and you have to watch the set time. There's simply less room for error with expansion anchors.


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## GBrackins (Apr 26, 2012)

cortell said:


> Epoxy is indeed stronger, but trickier to install. In order for it to work well, it has to be mixed precisely, the hole must be cleaned thoroughly, and you have to watch the set time. There's simply less room for error with expansion anchors.


read the directions, most epoxy have a temperature limitation, don't use above a certain temperature and below another.


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## Thurman (Feb 9, 2009)

I had an offer to build/replace a Pergola which would be very close, but not attached to the house, and NO fasteners would be showing when finished. It took some thought but I did it. There were also seven (7) 4x4 post holding up the far end of the Pergola which was the end near the pool. I suggested removing five of these 4x4's and replacing the end posts with 6x6's with decorative trim added. The trick was to place four (4) 6x6 post at the house with 1" of space between the post and brick and not to have fasteners show. I drilled the bottom of the 6x6 post for a piece of 1" rebar, then drilled into the concrete patio a 1 1/2" hole. I put the rebar into concrete with epoxy then stood the post up and onto the rebar also using epoxy. The real trick was to attach all the "runners" to the PT beam by using lag bolts passing through the beam and attaching the runners to the beam tightly. Then I had to cut decorative finials to add to the outside of the beam so it appeared that the runners actually went through the beam in some manner. Do your thinking and pre-planning, there is a way to do what you want done.


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