I am installing 3/4" oak on a 1" plywood sub floor. I used a self-leveling compound to fill a 1/4" plus dip in my hallway over a distance of about 4 feet. It turned out perfectly flat and level and tapered nicely on all edges. I am using 2" staples and was wondering if I am going to have problems with the cement breaking under my hardwood during stapling. Is this practice ok, or does the cement compound need to be removed before continuing. Also, maybe glue over the compound?? This self leveling compound adhered very well to the plywood and might be a pain to remove, but I will do it if necessary....Thanks for any help. I plan to start laying tomorrow

Usually it is not a good idea to patch on wood if nailing but if you used the primer it should stick and not bust out but I would just test it first and maybe glue it if the test woirks out ok. Get a scrap piece of wood, top nail it down and drive a couple staples in it see if it holds. Maybe some one else here has used it in that manner successfully but I have not tried it.

IMO with the movement of a wood subfloor over time,and the fasteners through the patch, and the movement of the Hardwood, your taking a chance. I would consider using a piece of 1/4" ply glued down , nail it in the thicker middle areas, then feather the edges with a sander.

Thanks for your help! I went ahead and cut out an 8' section of the subfloor and leveled the floor joists and replaced the plywood with lots of screws and PL Premium. Very glad that I did because that self-leveling cement was just crumbling.