BSTAR, whoever is laying the battens should pack and plane them . The slab will not be 100% and any rises or troughs are easily seen after the floor is laid especially up against walls where there is skirting or against a kitchen kickboard. We've seen a few that weren't done this way and the floors looked like a roller coaster. Very poor result considering how much some of these people paid the flooring companies to install these timber floors.
Stewie
Yeah i agree they shoud. But I just dont see all installers doing it. They will most likley blame the concretors who poured the slab.