I am about to install new 3/4-inch solid hardwood flooring in a 2nd floor apartment -- a living room, 2 bedrooms, and 2 closets. The new hardwood will be prefinished and probably will be Bruce solid maple flooring from Home Depot or a similar source, such as:
I am buying the materials. The installation will be done by either a hardwood floor company or a contractor that I use for other work.
Shown below are links to two photos of the existing subfloor. I posted the same two photos in two different formats in case one works better than the other, but the two sets of photos are the same.
The door in the upper right corner of the first picture in each set is the entrance to the apartment. The pictures were taken with my back facing the front wall windows of the living room.
We had to take up the original hardwood flooring for a number of reasons, including that the floor had squeaks all over in all rooms. We are now in the process of re-nailing all of the subfloor boards to get rid of the squeaks and secure them tightly to the floor joists.
My questions are about how to do the installation of the new hardwood.
One question is which direction to lay the new hardwood. The existing subfloor goes across the floor joists, so I am wondering whether to install the new hardwood in that same direction as the subfloor, or install the new hardwood perpendicular to the existing subfloor.
If the new hardwood goes in the same direction as the subfloor, it will be across the floor joists which I assume is good. But, that would mean that some of the hardwood seams will be right over the subfloor seams, which may not be a good idea.
If the new hardwood goes perpendicular to the subfloor, then the lining up of the subfloor seams with the hardwood seams won't occur, but I wonder if that would be less strong since the hardwood then would not be going across the floor joists.
Another thought is whether to put down something like a 1/4-inch plywood second subfloor over the existing subfloor first, and then put down the new hardwood. In that case, the new hardwood could go perpendicular to the floor joists for strength (the way the first subfloor is now) and it would not have the issue of the hardwood seams lining up with the first subfloor seams. Is that a good idea?
And, finally, what goes under the new hardwood? I have read that it is good to put down some type of underlayment such as red rosin paper. I even saw on the Home Depot website (I think) where they suggest using roofing felt for the underlayment.
So, the question is, "What type of underlayment should I use under the new hardwood?"
Since I will be asking one or two hardwood flooring installers to give me an estimate for doing the installation only, I know that I will get some ideas from them. But, I always like to check here in addition so I have more information to work with when contractors come out to look at any job I have.
Thanks.