I'm having to replace a water-damaged section (~100sf) of hardwood floor on 2X4 PT sleepers on a concrete slab. The water was on the floor for 6-8 weeks, so most of the sleepers under the damaged section have got to come out too. Problem is, the "2X4s" are a 1/4" thicker than what you buy today. Does anyone know, or have any ideas, of what I can use to replace the damaged sleepers that will match the sleepers under the rest of the floor?

I had thought that all I would need to do is cut some 4X4s down to size, but I can't find any kiln-dried 4X4s, except for Douglas fir. Would Douglas fir hold up well enough, do you think? I'm in south Alabama, BTW. If not, is there another option?

Any advice would be much appreciated.

D. fir is termite resistant, but using for sleepers over concrete is not a good idea, especially if you are going to cover the sleepers with 6 mil plastic sheeting. Can you find some cork sheet that is the right thickness to even out everything. Cork would hold up well.

I had not thought of cork, but I'm going to see what I can find based on your suggestion. Just to be clear, are you suggesting I put 1/4" cork on top of KDAT 2X4s, and then 6 mil plastic on top of that?

There actually is no vapor barrier under this 72-year old floor, but I was going to put one down where I'm lacing in the new floor, for whatever that's worth.

Thanks a lot for the advice.

Let me revise my reply. The reason I haven't considered using cork to make up the 1/4" difference is because I assumed it would tend to compress and leave me with an uneven floor. Based on your suggestion, I take it that I was mistaken about that? That said, would I use 1/4" cork, or slightly thicker to allow for some compression?

Again, I really appreciate your help on this.

The 3 1/2 inch of the top of the sleepers will be enough surface to support the floor. Cork is pretty dense and rot and termite proof.