This article is about how to anchor post to concrete. This diy step by step project project is very useful, as when building a deck, a railing or a fence, you need to anchor posts to concrete. The techniques needed to attach the wooden posts to concrete are straightforward, as anyone can get the job done very quickly. First of all you have to buy the post, as to know its dimensions when buying the hardware post anchors.
The post anchors come in many forms and dimensions: from standoff post base, up to uplift post base. In addition there are regular post anchors, for home improvement projects, and heavy duty post anchors for greater stability. Irrespective of your needs, you also have to know that there are also adjustable anchors, for attaching posts to an unleveled concrete surface. They are more expensive, but at least you know you are able adjust the height of the posts, as to make sure they are perfectly aligned one with another. See all my Premium Plans in the Shop.
In order to anchor post to concrete, you need the following tools and materials:
Materials
- 4×4 lumber – POSTS
- post anchor – METAL ANCHORS
- 2-3” lag screws – LAG SCREWS
- plastic dowels – DOWELS
- wood primer – PRIMER
- post anchor base
- lag screws
- sleeve bolts
Tools
- Level, measuring tape, framing square, carpenter pencil
- Hammer, rubber hammer, Circular saw
- Drill machine and drill bits
- Electric screwdriver with torque control
Tips
- Read safety and disclaimer pages
- Select with great care the wooden posts, to match the railings design
- Use a good drill machine with torque control
- Before fastening the posts, make sure they are plumb
Installing post anchor
In this project, we show you how to anchor post to concrete. In our case, we had to build stair railings and consequently we needed to attach post to concrete.
First of all, you have to take a look on the concrete surface, as to see if it is level. If the concrete flooring isn’t level, then you have to buy adjustable post anchors. Although they are more expensive than regular post anchors, they will allow you to adjust them to the other posts.
Next, we have to build the wooden post, that we want to anchor to the concrete platform. Consequently, you could either buy 4×4 pressure treated lumber or buy fancier decorative posts. Irrespective of your choice you have to adjust them to the needed length (usually around 3’/1 m), before fitting them into place.
In order to cut the wooden posts we have to use either a circular saw or a wooden chainsaw. We strongly recommend you to use a good circular saw, as it is better for an unexperienced diy-er. We have used the chainsaw, as we were pressured by time.
After you have adjusted the post to the needed dimensions, you have to install the post anchors to concrete. Consequently, in most of the cases the metal anchors have to be fastened to concrete, with several plastic dowels and lag screws. Align the anchors one with another, before making the marks.
In order to dill holes in concrete, we used a good drill machinery and masonry drill bits. Make sure the drill bits are in good condition, otherwise you might damage the drill machinery. You can use sleeve bolts as well.
After we have drilled the holes in concrete, we have installed plastic anchors, using a rubber mallet. Make sure the heads of the dowels are aligned with the concrete surface, otherwise you won’t be able to install the post anchor properly.
Next, after we have inserted the plastic dowels in holes, we have to drive in the screws , as to fasten the post anchor. In order to lock into position the metal hardware, we used a wrench key and 3” lag screws.
How to anchor post to concrete
After you ensure the post anchors are locked into position, you could proceed to installing the wooden posts. Consequently, in order to anchor a post to concrete, you need to paint its bottom section with wood primer, as to make sure it will resist against moisture. Sand the bottom section with a band sander, it it doesn’t fit in the anchors.
Attach the post in the anchor, tapping it slightly with a rubber mallet, until it sits properly into position, but don’t drive in the lag screws yet.
Use 1 1/2” lag screws to secure the post into position. Consequently, the last step when anchoring a post to concrete, is to drill pilot holes with a drill machinery through the holes in the post anchor. Use a thin drill bit, otherwise the lag screws won’t secure properly the post.
After driving in the lag screws, we have finished anchoring a post to concrete. The wooden post is plumb, as we have used a spirit level, and it is secured properly with 4 lag screws. There are many types of anchors you could use for your project, therefore use the ones that fit your needs an match the rest of your backyard.
Thank you for reading our article on how to anchor a post to concrete and we recommend you to check out the rest of your projects. Don’t forget to share our projects with your friends, by using the social media widgets.
Where can I get the metal 4×4 post anchors in this arrival?
I bought them from Europe several years ago. I’m sure you can find something similar in the large DIY stores.
What brand of 4×4 mounting brackets are depicted here? They appear much more stout than the Simpson E-Z Base brackets. Would love to get some of these!
Thanks!
As I have already mentioned in the previous comments, I bought the brackets from a DIY store a long time ago. There are generic anchors, no specific brand, so I can’t help you with this. The Simpson brackets should work as well, from what I see.
my God that’s ugly
Looks like the aftermath of hurricane Katrina. Is this a before or after picture ? Mr. Weaver , I concur.
Looks like leftover hurricane debris.
Are my eyes deceiving me or did you not even attach 2 bolts to the post anchor on the lower step??? I’m sure that will hold up just fine…..right.
The step was not aligned with the deck, so they is why half of the base plate is outside the concrete surface. However, everything got covered in concrete and then tiles. Everything holds perfectly after 8 years. I was just showing my project, it doesn’t mean you should install the base anchor like that. I just didn’t have another option have have the railings perfectly aligned.
It’s a great post. Thank you for your time!