On-site versus Factory Finishes
Because flooring is subject to minute inspection and must withstand substantial wear and tear, a thorough consideration of all factors involved is advised in the decision of whether to use on-site finishing or a factory-finished application.

A high-quality, site-applied finish requires planning, adequate time and careful attention to detail. That deep, glossy, finished look involves repeated sanding, proper cleaning and multiple finish coats. Finishing floors on site requires more time and skill than installing factory- finished materials. Finishing a hardwood floor in the field can tie up a work site for five or more days and requires extensive preparation. Other work that could jeopardize the quality of the finish will have to stop, adding time to any construction schedule. Many designers prefer the rich look of flooring finished on site and the consistent finish that can be uniformly applied across the entire installation.

At MoMA, the wood flooring was finished on site. "That involved the standard Museum of Modern Art practice, which is to put on two coats of linseed oil and then wax the floor. No urethane," says Berk. "Many museums-the ones that have a lot of wood floors-have something like that. They use some kind of traditional finishes like oil and wax-this is partially because the off-gassing of certain chemicals is a problem."

To address any potential off-gassing problems, BLT Architects' Aires says, "All adhesives, sealants, paints and wood finishes used in the Penn State construction were specified to meet LEED's low-VOC requirements. Because this project was a university-funded venture, an open spec was necessary. Wood finishes and polyurethanes specified included low-VOC products."

In contrast to on-site finishing, factory finish is a trend that is gaining in popularity. With factory-finished flooring, the manufacturer applies a finish at the factory, typically at least four coats of ultraviolet-cured urethane resin. Manufacturers say these finishes are more consistent and durable because they are applied under strict controls. Factory- finished floors can be installed straight out of the box, which can make the job easier. Factory-finished hardwood products can offer consistent quality and quick installation due to the following factors:

• Controlled Environment. Manufacturing takes place in a controlled environment without the need to contend with the effects of other building trades working nearby. Dust, traffic, temperature and humidity are out of the picture.
• Consistency. Factory-finishing operations work with low-pressure, high-volume spray guns and spray booths, and roll-coating tech- niques, so uniformly good appearance from piece to piece comes much more easily. Maintaining consistency across a whole installation is another matter-when cutting and mitering expose fresh wood, a factory finish is difficult to match, and touch-ups are tricky if there's damage on a busy jobsite. Finish-matching is easier, however, if you ask the supplier for a touch-up kit. Most manufacturers will supply stains and coatings from the same batch used on your materials, with instructions. A factory-finished floor will not be as flat as a site-finished floor. Some "overwood/ underwood" should be expected.
• Additional Steps. On-site finishing is generally a process consisting of three steps-stain, seal, and finish coat. But a manufacturer can go through four, seven, even 13 or more steps with additional sanding and extra finish coats that add richness and depth. However, if both processes are completed professionally, a site-applied or factory finish can be the same.
• Cost. Per linear foot, factory-finished hardwoods can cost substantially more than unfinished products. But despite high upfront costs, installation is quicker and less expensive, without the need to be concerned about regulations for stain and finish material waste disposal.

Says Terry Jackovic, Senior Manager, Facilities and Real Estate Development at American Eagle Outfitters, "We have done both finished in-place and pre-finished over the years. Depending on the look, costs, durability, installation time, etc., we think there is no substitute for the authentic feel of a finished-in-place floor. But quality control and installation time can be a challenge. Although the finish-in-place products are excellent these days, pre-finished allows us to move a little quicker, control the finished product better and maybe gain a little in durability. We typically use pre-finished except on rare occasions."

Atwater Commons dining hall floor at Middleburry College in Vermont is 6,500 square feet of hard maple, entirely harvested from campus-owned forests. Serving 700-900 students daily, the floor holds up well. Once yearly, it is buffed down to the bare wood and a low-VOC, water-based sealer is applied.

Maintenance

For the most part, hardwood floors can be maintained with simple, routine cleaning measures.

The main damage to a wood floor comes from debris. Dirt, dust and grit can dull a floor's finish and cause scratches that can only be repaired by refinishing. Regular sweeping with a broom that features exploded tips to trap dust and dirt, not simply spread it around, is recommended. Vacuums with beater bars can cause dents in the floor's finish. Regularly cleaned matting systems at the building entrances help trap dirt and grit.

Regardless of its finish, a hardwood floor will quickly lose its luster if exposed to excessive water, and may even warp. Some steam cleaners are appropriate for use on wood floors, but if the finish is worn or scratched, steam could seep into the wood, eventually causing damage.

Another concern is ultraviolet radiation in sunlight which can cause discoloration over time. The ultraviolet rays that can burn and age skin will affect any organic material, including wood. Prolonged exposure to sunlight will change the color of virtually any wood floor, regardless of the stain or finish. Some woods lighten when exposed to sunlight. Others, like cherry and oak, tend to darken. Some finishes feature sunscreens to help block the penetration of ultraviolet rays, extending the time it will take the wood to change.

"We don't do a lot in the way of exotic maintenance," says American Eagle's Bezek, explaining that quarterly cleanings and application of a low-sheen maintenance coating are standard. "We are not adverse to some natural wear that goes with the casual feel. This is one point we feel finished-in-place wins out. The wear is more natural," he adds.

On the other hand, at MoMA, the floors are groomed virtually on a day-to-day basis and maintained with wax. "This has been something that a lot of museums insist on, which we don't always recommend to people," says Berk. "But they have the resources for continuous maintenance. It's very labor intensive, and requires a lot of money and time, and MoMA has been doing it very successfully. They wax, they clean, they remove wax, they rewax, and it's held up very well. They have a major maintenance contractor and they budget for it, which most places can't afford."

Particularly with the advent of high-strength finishes, American hardwoods are a viable choice for high-traffic settings with the added benefit of warmth, elegance and richness. Their other attributes make them economical, sustainable and healthy choices as well.

The Hardwood Council serves architects, designers and builders by providing useful information about North American hardwoods in sustainable design and building. As an independent, nonprofit organization, the Council advances better understanding of hardwood flooring, furniture, cabinetry and millwork, without bias toward specific products or manufacturers. For more information about The Hardwood Council, and North American hardwoods, please visit www.hardwoodcouncil.com