I want to install a nailed down hardwood floor in a bonus room above my garage. The problem I am having is figuring out how to do this with the steel beam running down the middle of the floor. I currently have 1/2" subfloor installed. The top of the beam is raised up from the existing subfloor from 1/8 to 1/2". I will be adding another 3/4 subfloor on top of the existing subfloor to strengthen the floor since I will be running the hardwood parallel to the joists. I obviously cannot run the 3/4 over the beam since that would create a hump in the floor. I was thinking of running the ¾ to the beam then filling in the 8” beam span with lauan plywood glued down. The problem with using plywood on the beam is that the beam is does not have an even reveal to the subfloor meaning I would probably then have to go back and sand down the lauan in places where it was raised above the beam. The other idea I had was to fill in the beam as close as possible to the top and then pouring in a floor leveling compound. I know that I will not be able to nail down the hardwood over the beam but an 8” span between fasteners does not seem like a problem. I would probably use a subfloor glue in that area to ensure a good hold to be safe. Any suggestions would be greatly appreciated.
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