Cleaning up sawdust

Q: We are building a house and put down pre-finished hardwood floors. The builder set a table saw on cardboard on our floors and has been cutting the trim and woodwork. There is sawdust everywhere on my floors and in the cracks.

Will the saw dust harm my wood floors? What is the easiest way to remove it?

A: I wonder why some of my fellow tradesmen take such risks with having to replace a new floor, when 4X8 Masonite sheets are a very inexpensive insurance policy. I would vacuum up the floor really well, and cover with Masonite.