This is an extension to a current deck. This was build with 4x6 posts which were cut down. So I need to add some 4x4 posts for the rails. However, I can not put these on the inside because the 4x6's are there. The deck is about 30" off the ground. I know I would need to add some support under these brackets for them to be bolted into, such as some 2x10's. I will look into if these meet code where I live. The other thing I could do is add the posts to the outside of the frame.