Hello, My name is John.

I usually do remodeling and repairs, I am installing the floor in my in-law's house.

I have done a few installations of hard wood, but with "normal" installations.

The floor is unfinished 4-1/4" x 3/4" Solid Ash. With straight cut ends.

The sub floor is old concrete with 1x4" sleepers with old 5/8" T&G plywood with some kraft faced fiberglass in between that has been down since about 1975 except for a few spots I had to replace to remove cat pee

Here are my questions.

1. Should I use 15 lb felt under floor, or something else?

2. From what I have read here, I should use 1-1/2" staples, is this correct?

3. Should I do something to join the square cut ends like biscuits, or something else?

4. What type of finish is easiest to apply? I was looking at Streetshoe, but Traffic seems to be popular too, has anyone had experience with Varathane water based floor finish?

does anyone have any suggestions?

Is there mastic over the concrete or any other vapor barrier? 5/8" ply is a little light like to see 3/4 depends on the spacing might get some deflection. I wouldnt worry about joining the ends the sidematch should suffice. 2part waterborne finishes are tricky and can be a costly mistake if you not comfortable with, they take some practice to get down right. dont wast your time or money on the varathane.

Hello John,

I agree with Kevin, you need to make sure there is a moisture barrier over the concrete. The number one cause of floor failure is moisture and if you have moisture in your concrete it could affect the flooring. If there is no moisture barrier there I suggest pulling up the plywood and placing 6mil poly sheeting over the 2 x 4 sleepers and then re-install the plywood. The last thing you want is to have your in-laws mad at you because of a problem with the flooring.
I also agree that 3/4" plywood would be a more solid subfloor. Check for deflection in the 5/8" plywood before you install the new flooring. Over the plywood and under the Ash flooring use #15 black felt paper as an additional moisture retard.
If the planks do not already have a tongue and groove profile on the short ends, there is no need to take the extra time to create a tongue and groove profile. The flooring will be fine without it.
When nailing the flooring you can use 15.5 gage 1 1/2" staples or 1 1/2" 16 gage L shaped cleat nails. For wide planks you normally with space the fasteners 6” to 8” apart and 1” to 3” from each board end.
Water base finishes work great because they allow the true color of the flooring to come out and they dry quickly and have low VOC's. If you have never refinished a wood floor before you may want to leave this step up to a professional.

Thanks for the replies.

It looks like there was some kind of vct or asbestos tile at one time. It was pulled up before the sleeper system was installed. It looks like somthing red or pink.

How would it work to lay a moisture barrier down, then 15 lb felt on top of the plywood.

I think the 5/8 is pretty good for deflection, I am about 290 lbs, and it doesn't move hardly at all.

It is looking like I am going to tear out the existing sleeper system.
For the new sleepers, from my understanding, I should glue and screw down treated sleepers 16" oc, then cover them with 6mil, then nail down 3/4" plywood. Is this correct?