How to Sand Uneven Hardwood Floors

Hardwood floors that are newly laid will have small variations between the boards and some unevenness in the wood. Before you finish the flooring, you need to even out that surface. A rented drum sander is the easiest way to do it. The general process is generally the same as stripping off the finish from an old floor for refinishing: grind down the surface with rough sandpaper; use finer sandpaper to smooth it out. Dust gets everywhere, so make sure to seal off the room, including closing the heating ducts.

• 1

  Knock down any raised nail heads on the floor with you hammer and nailset.

• 2

  Load the drum sander with its roughest paper (20- to 40-grit). Set the sander so the paper is off the floor, using the raising lever or tilting back the machine, depending on the model. Turn on the sander and let it get to top speed. Set the paper to the surface and begin moving it immediately.

• 3

  Run the sander in a direction diagonal to the direction of the floorboards, letting it grind down the variations between the boards and any uneven areas. Don't let the sander stand in one place at any point while it's running.

• 4

  Vacuum the floor of all dust.

• 5

  Set up the drum sander with medium-abrasion paper (60- to 80-grit). Repeat the sanding process, but run the sander in the opposite diagonal direction as before, evening out the uneven edges of the boards that weren't fixed by the first sanding, and smoothing out the surface.

• 6

  Vacuum. Run the sander a third time, with the finest level of paper (100- to 120-grit), going with the direction of the boards. It should get the floor flat and smooth.

• 7

  Vacuum thoroughly.