I’m prepping to install ½” thick Armstrong Engineered Hardwood 7” tongue and groove planks in the kitchen and family room in our 1964 home. I have several questions about preparing the subfloor and here are some details.
There are 1x6 planks running perpendicular to the joists and fastened with T-nails. There are gaps between each board and the floor squeaks badly, partially due to removing ¾” hardwood flooring from a portion and removing 1/2” OSB from another portion. I’m planning to use ¼ or 3/8” CDX as another subfloor/underlayment to cover the gaps and raise the floor to better match the height of adjoining ¾” hardwoods and some tile.
1) I plan to screw each subfloor plank down to minimize the squeaks (2” #7 or #9 screws).
2) What construction adhesive is best to use under the plywood?
3) I’ve read to only attach the second subfloor to the planks with staples (to decouple), not all the way to the joists. And leave gaps between the sheets and around the perimeter.
4) Do I run the plywood sheets perpendicular to the planks?
5) With the planks and plywood, can I run the 7” Eng HW either direction? Thanks