Slighty uneven floorboards and laying hardboard

[ma123]

I have recently bought some hardboard which I am going to start laying over the floorboards in my rooms. After that I will fit carpet. The floorboards are not too bad, but in some places they dip slightly and some floorboards are slightly lower then others. The unevenness is only in a few places on the floors and in many cases is just a small part of the floorboard, so don’t really want to replace floorboards. However I am worried this unevenness may make the hardboard bend/creak slightly when these parts are walked over. Is there anything thin I can put down just on these few parts of the floor first before laying the hardboard which would even these parts of the floor?

 

[dazlight]

Yes mate, fill in any holes with a filler, or use gripper adhesive, comes in a tube. Then put a latex screed over bad parts of the floorboards. Plywood would be better as its stronger but If u have bought the hardboard use that.
Nail it every 6"

 

[tony1851]

If using hardboard, don't forget to wet it thoroughly on the back (rough side) and leave for a good few hours - preferably overnight -before nailing down. (use a scrubbing brush to work the water in).
This makes the board expand slightly, so that after nailing down, when it dries out, it will shrink and tighten up hard down on to the floor boarding.
If you put it down dry, it can sometimes cockle-up as it gadually expands through picking up moisture from the air.