Refinishing hardwood floors is a messy job. Dust seems to get everywhere, which is the bane of floor sanding contractors. It can be difficult enough to deal with in a residence; in a commercial environment, it can be a disaster. Not only is it timely to clean up but the special HEPA vacuums and air filtration devices required to do the work efficiently are not at everyone’s disposal. What’s more, wood dust from the floor sanding process, including the removal of finishes like urethane, stains and the aluminum oxide base, is a serious hazard to human health if inhaled, putting floor sanding contractors at risk.
Dustless sanding has reinvented wood floor refinishing. It not only eliminates 99 per cent of the dust from the entire floor sanding process but it is also a drastically faster method of refinishing hardwood floors and keeps the air clean. This method is not to be confused with sandless refinishing, which, as the name implies, involves no sanding. Dustless sanding, or dustless refinishing, includes a sanding component. Both processes have the capability of changing the colour of the floor.
Dustless refinishing of a floor centres around ways to eliminate or minimize dust generated through the sanding process. The floor is cleaned and then sanded with a drum sander that has a special shroud built around the machine. The sander is then attached to a HEPA vacuum or a vacuum located outside the premises, which collects the dust during the sanding process. Some specially made vacuums have a cyclonic effect that will cause the machine to reverse at regular intervals. This ensures the intakes don’t get plugged with a lot of heavy dust, resulting in a loss of suction.
Once the floor is sanded, it is coated with a sealer or stain. This is followed by applications of a urethane finish. Between layers of finish, the technician will typically screen the floor with a 175 RPM (revolutions per minute) swing machine. The machine used in the dustless refinishing process also has a dustless shroud around its base to keep the dust generated from aerosolizing. This is important because wood dust has been associated with health issues due to the natural chemicals in the wood, such as bacteria, moulds or fungi, and is considered carcinogenic, according to the Canadian Centre for Occupational Health and Safety.
Sandless refinishing involves a topical re-coating of the floor. It used to be that the floor would be ‘buff-coated’ by screening the existing urethane finish of the floor and then a new topcoat applied to the existing finish. With innovations in manufactured floor finishes, companies that perform buff coats have discovered the application of a new finish does not always ‘take’ to the old one. The floor being refinished may have some proprietary Teflon-type of coating that prevents a new topcoat from adhering to the original finish. (The new finish may appear to have adhered to the floor but in reality, it is just sitting on top of the old finish, held by nothing more than gravity.) Shortly after application, the new floor finish will start to shingle and peel off. For engineered wood flooring, which consists of only a thin layer of hardwood on top of many layers of wood product, this can be very problematic and may actually necessitate entire floor replacement.
Sandless refinishing is usually accomplished now in three quick and easy steps, allowing floors to be back in business the next day. The first involves a thorough cleaning of the floor with a special auto scrubber. Beforehand, it is important to confirm whether this may be done as some flooring manufacturers prohibit the use of an auto scrubber of any kind on their flooring. Next, the flooring is coated with a special adhesion product that acts like a bonding agent between the existing floor and the new topcoat; however, it’s actually a finish. A final topcoat is then applied to the adhesion layer. There are now products that include a tint in the finish, which allows the floor refinisher to change the colour of the floor.
Whenever re-coating a floor through a sandless refinish or re-coat system, it is wise to first perform a test in a small area to ensure the product will adhere and not come off. Soiling, films from cleaning solutions and manufacturers’ proprietary finishes are all root causes of flooring re-coat failures.
James (Lee) Senter is president of Fresh and Clean, which performs deep cleaning of floors in the Greater Toronto Area, and CEO of restoration company DryIt. He is also president of the Canadian Flooring, Cleaning and Restoration Association (CFCRA). Lee can be reached at [email protected].