I tried this post on the general board with no response, so I'll try here. I have badly checked floors from low RH, I have fixed the humidity problem but was wondering what to expect if I sand and refinish these floors.There are many hairline cracks - checks, will they be very noticable when refinished?

If the cracks and checking are in the top veneer layer, they may still be visible somewhat. Trowel filling the floors during the refinishing process will address some of them. I wouldn't trowel fill a beveled edged floor however, only a square edged. I'd go with a stain ( if you want it stained) and four coats of a high quality water based poly.

Thanx for the reply Gary. Another question when refinishing a prefinished micro beveled edge floor, there really is no way to sand the beveled edges, will this affect the new finish being applied. Or should you sand enough to eliminate the bevel if possible.

If the top layer is thick enough, you could sand down to the point where it is flush. Typically, those small grooves do not present a problem when refinishing as long as they're pretty clean.