Q: I have been in my house less then a year. We have distressed oak floors with a lot of character, which is fine, but there are numerous spots where the wood is cracking along the grain-enough to catch a sock.
Were they not finished properly? Another sanding and coat of polyurethane needed?
A: Cracks developing has nothing to do with the sanding. The boards were probably “defective” before they were installed and then with dryer conditions inside the house they may have shrunk a bit and the cracks revealed themselves.
You can either have the boards changed, or something you might try is injecting some type of adhesive into the fissure to stop it from opening further. If the adhesive dries below the surface you can then fill up to the top of the board with colour match wood filler. Try not to get the adhesive on the surface of surrounding boards. Cyano-acrylate adhesive may work well in this instance. It dries clear.
Related Q: Our newly installed hardwood floors have a plethora of deep cracks along and through the grain of the boards, which one can see from outside the room in multiple boards; some cracks are extended through the knotholes in the custom cut combination #1 and #2 Red Oak hardwood floorboards and seem to extend through the thickness of each board.
Should we allow the installer and contractor to do as they have proposed and re sand and fill the cracks and then apply another coat of finish, or should the custom cut hardwood floor system be replaced?
A: Not surprising you have so many split boards given the low grade of the oak. I would recommend replacing the bad boards and then sanding over. Sanding and filling won’t make the deep cracks disappear.