Advertising supplement provided by The Hardwood Council
For on-site finishing, the best option remains polyurethane. Waterborne finishes are not suitable for finishing casework, millwork or flooring onsite, according to the Architectural Woodwork Institute (AWI). AWI cautions that “governments, owners, and design professionals who insist on waterborne finishes at this time in their development must assume the responsibility for the inherent risk that the finish will not appear and/or perform as well as a comparable solvent-based product.”
Finish costs vary greatly and although superior performance finishes are most expensive, overspecification can add unnecessary costs.
Surface finishes are durable, moisture resistant, easy to maintain and appropriate for many applications. Available top coats include oil-based urethane; water-based urethane; moisture-cured urethane and conversion varnish. Some polyurethane finishes contain aluminum oxide to enhance a floor’s abrasion-resistance qualities.
Acrylic-impregnated floor finishes, among the most expensive, are used in ultra high-use commercial settings, institutional or health care settings, for an extremely hard, durable barrier to dirt, moisture, and wear.
“We reserved the acrylic-impregnated woods primarily for hardwood flooring in our hospitals as well as some of our corporate environments,” says McFadden. “We have used a catalyzed finish on some of these hardwoods and wood veneers, wherever we’re going to have any sort of water coming in contact. For instance, we’ve used catalyzed finish in a serving area within a hospital mainly so that it can hold up and withstand the steam that is coming off the food. Typically, throughout all of our regular corridors we really have used a very light stain or else just a clear finish with just a polyurethane-type sealer.”
At the Dollard Health Center, a low-VOC finish was used to seal and preserve the woodwork. “The indoor air quality issues surrounding hardwoods are very good,” says Syrett. “Guenther 5 uses an index similar to William McDonough’s, where healthy materials are given a ‘green’ rating and materials to avoid are given a ‘red’ classification. We place hardwoods in the green category as long as the substrate is done right and a proper sealer/finish is used.”
In the Lewis and Clark Building, the design team specified two field-applied low-VOC finishes, both meeting SCAQMD (South Coast Air Quality Management District) Rule 1168. The purpose of Rule 1168 is to reduce emissions of VOCs and to eliminate emissions of chloroform, ethylene dichloride, methylene chloride, perchloroethylene, and trichloroethylene from the application of adhesives, adhesive bonding primers, adhesive primers, sealants, sealant primers, or any other primers.
The oak floor finish contained only 70 grams per liter VOC; it was a waterborne natural clear finish with a rapid dry time and high scuff resistance. The product’s spec sheet recommends sealing the unstained floor with one coat of sealer, and then applying two coats of the 70 finish.
In a house she designed in Sante Fe for yoga instructors, Baker-Laporte used the principles of Bau-Biologie, a movement promoting healthy building as a way to improve living and work spaces and the health of people who occupy them. She specified a field-applied breathable hard wax finish that will be reapplied every few years. The wax was made from readily renewable and natural ingredients.
“A material that is harder and can be cleaned easily and well is good for everybody–it doesn’t accumulate dust and it doesn’t accumulate mold,” says Baker-Laporte. “Hardwoods have the perfect combination of durability and give. A hardwood floor, depending on its installation, is much more giving than a concrete or tile floor. It’s kinder to the body.”