Hello again!

Two quick questions:

1- I am replacing the 5/8" particleboard that is installed over another layer of 1/2" plywood. The instructions state to use CDX plywood. What is CDX plywood and how will I know the difference when I go to purchase?

2- The 3/4" hardwood flooring will be installed with an expansion gap around the perimeter of the wall. When installing the 5/8" CDX plywood, should I also leave an expansion gap?

Thanks!

PS: Since posting this message, I visited our nearby Lowe's store and enquired about CDX plywood. The associate didn't have a clue as to the differences and obviously I don't. So, any help here will be appreciated! Oh ....... I checked the info tags over each plywood product, but found nothing referring to CDX on any of the sheets.

Yes, I leave a ½" of space around the perimeter, when doing subfloor.

It should be on the ink stamp, running down the middle of the sheet, on one side. CDX.

Do a google on plywood grades.

That don't surprise me about the store help. The rack should be tagged 15/32 CD sheathing, it is available either 3-ply or 4-ply, either one will work. The Lowe's number for 4-ply is item# 12247.

Leave an 1/8" around each sheet and cross lay it over the subfloor, all seams staggered.