Q: I have parquet floors that I installed 4 years ago. The floor is scratched in some places, so I am going to sand the floor. My question is: is there anything that I can use to fill the spaces / gaps in the tiles?
A: There are some decent, easy to spread and sand, pre mixed water based fillers on the market, including products from Bona Kemi, Woodwise, and Dura Seal. Your nearest hardwood retailer should carry one of them.
Follow-up Q: After the floor has been filled and finished, is the filler still noticeable?
A: It can be noticeable. There still is not a perfect filler to be found on the planet.