# 4x4 to concrete slab



## Sam60 (Apr 29, 2006)

Need to install wood posts and rails on a small front porch which is concrete and top slab is about 7’ x 4’. There is no roof over porch

Before I have always just put the post in front of the porch and went all the way into the ground instead of trying to anchor a 3 ft tall 4x4 on top of the porch slab.
I have never used the Simpson galvanized brackets made for this because they just don’t look like they would be very strong.
It seems to me there should be a better way or a different bracket that would be stronger so doesn’t have to worry about if the post will wobble some. I know adding the railing will add just a little stability.

Any suggestions?
Thanks


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## DrewD (Jun 10, 2007)

The simpson brackets are really rugged, they hold down PT 6x6 deck posts. I don't know why they wouldn't work for your railing. Use a tapcon and drill into the slab. Should work fine.


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## BKFranks (Feb 19, 2008)

The Simpson column base that uses an anchor bolt into concrete is pretty strong. ABU44 for example: http://www.strongtie.com/products/connectors/AB-ABA-ABE-ABU.asp


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## Sam60 (Apr 29, 2006)

BKFranks said:


> The Simpson column base that uses an anchor bolt into concrete is pretty strong. ABU44 for example: http://www.strongtie.com/products/connectors/AB-ABA-ABE-ABU.asp


From the info on the link you supplied
"Post bases do not provide adequate resistance to prevent members from rotating about the base and therefore are not recommended for non top-supported installations (such as fences or unbraced carports). "

Seems my installation would be much like a 3 ft high fence. 
Also dont think can compare to a 6 x 6 deck post. Once installed on a completed deck with the framing and rails I dont think the average person could lean on or move a 6 x 6 post even if it was not even anchored to the concrete base with anything.

Mine would be replacing old metal porch rails that could sometimes may even have kids climbing on then so would need to be as safe as the old ones.


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## neolitic (Apr 20, 2006)

I don't know where you are,
since you choose to keep tha
a secret, but here in the land 
of freeze and thaw I have never
seen *any* surface mount system
hold up over time for railings
on concrete.
Maybe try drilling steel dowels
set in PorRock or epoxy, and
set the posts over them?


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## BKFranks (Feb 19, 2008)

How about using some 1/2" all-thread, drill the concrete and epoxing the all-thread in leaving it stick up about 9". Then attach the posts like you would newel posts on a set of stairs. Will that be strong enough for your 3' posts? Once you crank it down it won't go anywhere.



This is a stair part:


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## Forry (Feb 12, 2007)

I've done a couple of those freestanding posts, and I used a custom made steel 2x2 post with a bolting flange welded to the bottom. Wrap it with 1x (3/4") material, and tap a shim down inside to make it snug. SOLID. Cedar, if milled nicely leaves barely noticeable seams at the mitered and glued corners...


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