Carpentry and Woodworking - installing interior railing posts

I'm replacing my interior railings with new stainless steel posts. What is the most secure way of attaching the posts? The railing posts have a thick 5"x5" steel plate with 4 holes. My floor is 3/4" oak on 3/4" subfloor. I'm thinking about using hanger bolts (plain steel, 3/8-16 x 2.5") with cap nuts. Should I use some kind of locktight to ensure that the hanger bolts are secure to the floor? Liquid nails under the plate? Any other tips?

Thanks...

--Rob in VA

I would add a 2x12 under the floor for attaching the posts, more support is always better with newel posts. Glue and screw it to the floor. Ideally, the post should bolt to a floor joist.

When installing newel posts, I use everything at my disposal for added security....glue, locktite....use everything. Ideally your hanger bolts would be secured into more than just 3" of material in the floor so adding more framing underneath would be ideal if that is a possibility. If you have any newels in a corner, 3" of meat underneath would be plenty as they are much stronger due to the rails coming from each direction. Newels on the end of a run or in the center of a straight run would ideally have additional framing underneath to grip onto a long hanger bolt. When calculating baluster spacing, I use an app for the iPhone called BalusterPro which makes those calcs quite simple. Here's a link www.gabrioconstruction.com

Good luck!