Gluing Post Base To Concrete

You have 3 main issues: 1) Hold your post and roof up, 2) Hold your post and roof down, and 3) Maintain a minimum of 6” distance from the post to the ground.

1. You need a steel connector with a mechanical anchor (bolt, etc.) to support and hold the post in position. There are several types of connectors that are suitable for retrofit applications...see below.

2. Likewise, a steel connector with a mechanical anchor will “hold” the post and roof down (providing the top of the post is anchored to the roof properly.)

3. The bottom of the post needs to be cut off so it’s elevated a minimum of 6” above grade.

Because the post is about 16’ long, I’d suspect that the roof could be temporarily supported so the post could swing out of the way a few inches so the anchor could be installed. I’d use something like the Simpson ABU 66Z

https://www.strongtie.com/resources/product-installers-guide/abu-installation

Get the correct type of galvanizing for your area.

I would do the following:

1. support the roof - and jack it up a 1/2” extra to enable the new one to slide in.

2. drill and cement or epoxy the post support ( stainless is good) into place, these are usually adjustable so getting the roof level is possible.

3. measure the required length of post - from the support to the roof and the 1/2” can be accounted for in the adjustment.

4. fit the post - the bottom support may be a “cup” which might need one side reducing or it may only be a U, which means the post end can slide in easily.

5. adjust the post height while removing the jacking supports.

May be worth treating the post ends and painting before fitting though.