Over the past ten years, I've installed all types of flooring and have seen all kinds of quality levels. The wood the Silvas chose for the Billerica house is among the best we've used. Hardwood comes in several different widths and grades. Strip flooring is typically narrow pieces of wood up to 2 3/4" wide, while plank flooring runs up to seven inches wide. Oak, the most popular hardwood, is graded as follows: Clear oak is wood that has very few flaws or character marks. Select oak has a bright grain, a few flaws, and most pieces match well. Number One Common has both light and dark pieces with some marks, while Number Two Common has all sorts of character marks like knots, worm holes and discoloration. In Billerica, we installed a custom-milled, 2 1/4" quartersawn white oak floor in the first floor rooms. To produce quartersawn lumber, a log is quartered and then awled perpendicular to its growth rings, producing narrow boards with great dimensional stability and attractive vertical grain. It will expand and contract much less than plainsawn lumber. Because of this quality, quartersawn oak is an especially good choice for installation over an in-floor radiant heat system such as the one used in Billerica. Quartersawing also produces something called "flake," a visual feature that, along with vertical grain of the wood, creates the classic look common to many Victorian homes in New England. Grade for grade, quartersawn lumber is more expensive than plainsawn because of its slow milling process and the amount of log that's lost in the quartersawing. Before the flooring was installed, we stored the wood in the house to acclimatize it to its permanent environment. During this process, we took moisture readings of the flooring and sub-flooring; when moisture-level readings were 6% for the flooring (because it will sit over radiant heat and tend to dry out) and 7-10% for the subflooring, we began to lay the floor. The custom milling produced precise boards of long lengths—eight to ten feet, as opposed to the three-foot-and-under pieces commonly available. (The floors of Victorian homes contain boards as long as 12 feet.) Its accuracy made the usually difficult process of installing the borders less difficult and simplified the sanding process, making the initial rough sanding less time-consuming and thus less expensive. While we usually start with an aggressive 40 or 36 grit sandpaper, in this case we sanded the floor with a series of 60, 80 and 120-grit papers on a belt sander and edger. We then finished the job with four coats of commercial oil-based polyurethane, with a satin sheen top-coat providing a classic Victorian look. For the upstairs floors, the Silvas chose a southern yellow pine, a common choice in Victorian homes for less formal rooms, such as bedrooms. The pine is not as hard as oak, but it too was quartersawn, increasing its durability. Absolutely clear, with not a knot in sight, it provided a beautiful light-yellow backdrop for the bedroom rugs and furniture.