Plywood on top of Sub-floor?

Hey All,
With alot of advice from the DIY forum I am putting in Dupont laminate in the first floor of my house. My house was built in the late 60's and has gone through several rennovations as shown by the 3 layers of flooring. I have everything ripped out down to the 3/4 by 4 T&G subfloor and am almost ready to start laying floor. The subfloor is flat however it has a million nail holes and is spongy in some spots. I want a solid floor so I asking you guys what you think about laying 3/8" or 1/2" plywood over the entire floor before the laminate goes in to add some rigitity. Thanks for the help,
Brian

 

Welcome to the forums

While I have only installed wood floors for myself I have remodeled quite a few MHs and often plywood over the MH floors to both hide the repairs and make the floor smoother and stronger.

I wouldn't rely on plywood alone to fix the spongy parts of the floor. Either the sub floor is bad or there is a floor joist issue. I would fix this first. If it is just a damaged piece of sub floor you can cut it out, replace with new and then cover it with plywood although if you have a tight fit it should be ok to go over it with the flooring.

The nail holes shouldn't affect the way the new flooring will lay. If they are really bad you could fill them.