A rather elaborate competition is underway to determine the best hardwood floor finish for THE CONCORD GREEN HOME. The good news is that there are many healthier alternatives to the ubiquitous and toxic polyurethane used on most US floors today. Some methods are brand new, some old and time-tested, and still others are from across the pond (Europe is often well ahead of the US in the healthy house arena).
The winning finish will:
- BE SAFE – Most floor finishes used in US homes today, such as polyurethane, contain toxins that off-gas long after the powerful fumes dissipate
- SEAL – Lock in the pine and oak terpenes and aroma, which are common allergy triggers
- STAY - Remain inert when in contact with underfloor radiant heat temperatures of 90 degrees (particularly as we are finishing all sides to achieve goal A.)
- PROTECT - Provide durable protection from traffic and moisture
- MAINTAIN – Be easily maintained with minimal resanding, another process to avoid in a healthy house
Admittedly, there will be trade-offs to consider with the final selection. For example, most “living finishes” such as oil, score highly on most measures, but fail to seal in the wood allergens. Meanwhile, the polyurethane alternatives do require periodic resanding (although new dustless methods are now available). Others still have some volatile organic compounds (VOCs) upon application, but dissipate more quickly than standard polyurethane.
Our search needs to include winners for both antique reclaimed heart pine flooring and painted oak flooring.
Sampling process underway. Each product is applied and then cured for one week, prior to testing, which includes visual and textural inspection, aroma sniff test, off-gas (seal in glass/foil and then open to see if any off-gassing remains), compatibility between under- and top-coats, etc.
Here are the contenders:
Under Coat / Sealer
Zinsser Bull's Eye Shellac – an old standby that is highly toxic on application but cures fast and completely
Bonaseal – a low VOC sealer that cures quickly
AFM Safecoat Zero VOC Flat Paint – may have sufficient sealing properties to be used as undercoat for painted floors
Mythic Paint primer - also may have sufficient sealing properties to be used as undercoat for painted floors
All-In-One Finish (some can be used over Undercoat as well)
Rubio Monocoat - VOC-free, non-toxic natural oil finish with better than average durability
Vermont Natural Coatings – low VOC polymer coating made with recycled whey from Vermont dairy farms
AFM Safecoat Polyureseal - low odor, low VOC polyurethane
Bioshield Furniture and Floor Hardwax - "healthy living hardwax" made from natural oils, carnauba wax with lead-free dryers
WOCA - Zero-VOC oil from Denmark with natural matte appearance
Top Coat Only
Bona Traffic or Bona Strong - similar low VOC, low odor polyurethane alternatives that cure quickly
A big thank you to Rick Woodland of Terrene Sustainable Building Supply of Acton (one of our project sponsors). He has taken on the task of creating approximately 25 different samples for our test. He has also been a tremendous help in researching the chemical and performance properties of our various contenders. Thank you, too, to Steve Rush of Rush Quality Environments, Debra Lynn Dadd of Green Living Q&A, Leslie of Otterishly (MCS Safehouse), and the various product manufacturers for providing us with important information and guidance.
If you have any other wood finish suggestions, or experience with any of these products, please submit them via Comments section below soon!