By Rusty Swindoll
Since 1922, the National Fire Prevention Association (NFPA) has sponsored the public observance of Fire Prevention Week. The 2018 campaign takes place Oct. 7-13, and while most people pay close attention to fire safety in homes, it is equally important to note fire safety precautions when on a jobsite. While installing or sanding and finishing hardwood floors, a little knowledge of proper prevention goes a long way in preventing a potential catastrophe.
An Ounce of Prevention
There are many different ways Class A fires can be caused and prevented on the jobsite. Spark fires can be caused by the sparks created when sanding over exposed nails or other metal objects. Always check to make sure nails are not exposed before sanding floors or ensure proper procedures are implemented when sanding floors where nails cannot be set. Spark fires can also be caused by improperly aligned equipment.
Friction fires can be caused by dull sanding paper, overworked paper, or improper selection of paper for the particular job. To avoid friction fires, be sure to switch out your sanding paper regularly and make careful paper selections.
Spontaneous combustion can occur due to wood dust igniting in the dust-collection bag when a new floor is being sanded. The heat created from the friction of the machine and sandpaper on the floor can increase to the point that the dust begins to smolder inside the bag, vacuum, or container. Wood dust must reach a temperature of 400° F (204° C) for it to ignite. Combustion happens much more frequently, however, when a floor is being resanded. The old finishes that are on the floor become ground into a fine powder. Again, the heat created by friction can cause spontaneous ignition. Resanding a freshly finished floor can pose additional risks due to the solvent and wood dust combination.
Sanding dust should be disposed of safely. Keep an eye on the dust collection bags, vacuums, or containers on all equipment. Empty the bags often in a proper container. Also, empty dust collection bags before transporting the machine or leaving the jobsite – even if you are just leaving for a short time.
Always remove dust receptacles and dust collection systems from the jobsite at the end of every day and properly dispose of them.
The most common type of spontaneous combustion in our industry is caused by stain rags that are not disposed of properly. Oil-based stains, natural oils, varnishes, shellacs, polyurethanes, and paint thinners are common products that can be culprits. Spontaneous combustion occurs when the solvent or substance begins to oxidize. This process causes an exothermic reaction, meaning it releases heat. If the heat has no way to escape, like in a pile of rags, the temperature will continue to rise to a level high enough to ignite the rags. A cotton rag containing any amount of stain residue has the perfect surface area-to-mass ratio to spontaneously combust. Therefore, you should dispose of rags in an airtight metal container.
Class B fires are caused by flammable liquids and their vapors. On a wood flooring jobsite, these can include things like lacquer thinner, mineral spirits, shellac, and conversion varnishes. You can minimize the risk of Class B fires by turning off pilot lights and all ignition sources before using flammable liquids on the jobsite.
Class C electrical fires are caused by faulty cords, loose connections, breaker box fires, bad switches, faulty equipment, or improper cord selection.
Your Most Important Tool
Contractors take great pride in their tools, and a fire extinguisher is an essential safety tool for every wood flooring job. Having a good understanding of the various types of fire extinguishers, and how to properly operate them, will minimize risk to you, your crew, your customer, your vehicles, and your jobsite.
Dry Chemical extinguishers are the type of extinguisher required for the hardwood flooring industry. These extinguishers, which are often referred to as ABC extinguishers, are clearly labeled. They are designed to put out fires by coating the fuel with a thin layer of dust, thus separating the fuel from the oxygen in the air. The powder works to interrupt the chemical reaction of the fire. While installing or sanding and finishing hardwood floors, it is important you keep ABC-rated fire extinguishers nearby to handle potential fires that could happen on the jobsite.
Educate Your Crew
Education is another important tool for you and your crew. Fires are caused, in one way or another. In some cases, the fire is a result of something a person did. In other cases, a fire is caused because of what someone has not done. In either case, the fire that results from these two different behaviors can result in total destruction.
Before starting any installation or sand and finish job, ensure that all crew members are briefed and updated on any possible fire risks.
Need to brush up on your knowledge? The NWFA has a fire and extinguisher safety course available through the NWFA University. Visit nwfa.org or call 800.422.4556 to learn more.
Rusty Swindoll is Technical Advisor at the National Wood Flooring Association in St. Louis. He can be reached at firstname.lastname@example.org.