How soon after the third coat of poly can you walk polyurethane floors?

Q: How soon after the third coat of poly can you walk on polyurethane floors / hardwood floor? How soon after the third coat of poly can you put the furniture back on the floor? Also, we have noticed what looks like dust or sanding particles in the finish. What is required to get those out without damaging the finish?

It looks like our installer did not use a tack rag.

A: Generally a floor finish is ready for light traffic with over night drying. I would suggest a full day or 2 before putting furniture back. No rugs for several weeks. If you have dust and debris in the finish the only way to deal with that is to buff and coat the floors again.