Q: We noticed a soft spot on our 2006 Infiniti four winds motorhome. We took up the laminate floor and cut out all of the soft spots. We are confident in putting the laminate back in, what we need help with is the subfloor.
Do we need to buy new wood and glue it down? If so what glue do we use? And do I need to square off or can I put pieces in?
R: It looks like the wood laminate was laid over a vinyl floor covering. You will want to make sure you fill in for that, with your subfloor, as well.
The biggest concern I would have is having support under any seams that you make. I would square it off, in to a larger area and, add some frame support along the seams. I have attached some information from my RV Damage Repair Estimator manual to help.
You have metal framing in the floor but, you can attach wood framing to it. This would make it easier for you. You wouldn't have to weld. You could use a structural adhesive or, bolts (Lag or nut and bolt).
You will want to laminate or glue everything back together. You will want to use a latex based contact adhesive to glue your underbelly skin, insulation, frame and subfloor together. You will need to add a piece of vinyl or some sort of filler and level the subfloor along with any seams.
I hope this helps. Let me know if you have any more questions.