Hi Jennifer, Just to add to what Robert has said, if they did indeed use nails to lay the tack strips down, you can get a cement filler from Home Depot or Lowes to plug up the holes so they aren't so visible.
They come in Caulk tubes, and you use a caulking gun to apply it into the holes. You then take a putty knife to it to smooth it out. I used this same stuff not too long ago to plug up some holes in the brick work around my house to plug any leaks coming in. Victor Gouveia
