Two reasons. Dustless sanding is healthier for you, especially if you have respiratory diseases or issues such as asthma or COPD. Secondly, reducing the dust in the air reduces the chance the dust causes imperfections in your coating.
Yes. Removing the carpet, pulling the appliances and toilets, removing the trim, removing the tack-strips, removing the tile, etc., will help save you money. We will not stain and finish behind a DIY sanding project. We will not sand ONLY, for a DIY project.
This depends on what type of polyurethane you are using oil-based or water-based. Oil-based tends to take longer – often 3-4 days plus drying time (longer if for larger jobs) and water-based tends to dry faster, so it’s often 2 days (longer for larger jobs).