I want to bolt posts to a concrete patio to make a roof. The surface of the concrete has texture to it. I figured the texture is meant for a better grip in wet weather.

Should I smooth out the concrete areas where posts will be, so the bracket and concrete have full surface contact or is it fine to bolt brackets as it is?

If I should - would some watery cement/sand mix do the job? Texture is 1mm pores at most, I was thinking of filling those up with cement or other solution.

  • 1
    Be aware that those brackets are not intended to hold up your posts. They just keep the posts from being bumped out of position. Your roof structure will need to be internally braced to prevent the thing from folding over. I mention it because that's been a common misconception around here.
    – isherwood
    Jun 23, 2020 at 15:21
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    Also be aware that your concrete slab may not be up to the task of supporting that much weight at concentrated points, especially near corners. You might crack it. Feel free to post more questions if you'd like a review of your design.
    – isherwood
    Jun 23, 2020 at 15:23

2 Answers 2


I'd just spread some siliconizer on the concrete and place the bracket on top. That will keep any water/moisture from accumulating under the brackets. In doing similar work, I've had great results using lag shields and stainless steel screws.


You may want to consider using an anchored post base like this:

enter image description here
Source: Home Depot. No endorsement of vendor or this particular product intended or implied

  1. Drill holes in the concrete slab,
  2. insert the threaded rod into the holes,
  3. epoxy them in place.

Bear in mind isherwood's comment about your patio possibly not liking the added weight of the roof. You may need to create a bigger hole to create an entire footing (going below your local frost line) for the posts, then put this anchor on top. Bring the surface of the footing to the surface level of the existing patio. You may want/need to install an expansion joint material like this:

enter image description here
Source: Lowes.com. No endorsement intended or implied. This was the only <$100 product in a reasonable size I saw.

Around the outside of the new footer between it and the existing patio.

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