A Guide to Cork Floor Maintenance
Cork tile has been around for about 100 years and is still widely used for floors and walls, especially commercially. If specified, installed and maintained correctly, it’s a beautiful, warm, quiet, “environmentally friendly” floor that will last for decades. I’ve worked with cork full-time for the past 18 years, both in sales and as a technical consultant. I chaired the task group that created ASTM F 3008, Standard Specification for Cork Floor Tile*, twice visited the cork forests and factories in Europe and have presented my seminar “The Fascinating World of Cork” to architects, floor coverers and interior design stu dents since 2002. And yes, some of my friends call me the “Cork Dork of New York” and I have a Facebook page by that name.
A “rapidly renewable material” from the Mediterranean region, cork is bark from the cork oak tree, which is harvested and re-grows every nine years or so. Cork bottle stoppers are the main product, and all the material that’s not used as corks becomes a variety of other products including tile.
Classified as resilient flooring, cork acts a lot like wood flooring, but has characteristics of both.
For example, installers need to pay attention to proper temperature conditions, acclimate material on the job site and install in a space that’s climate controlled. Also, don’t install cork in very wet or sunny spaces, and maintain cork just like wood flooring.
How durable is cork? Durability is all about taking good care of the finish, using cork where it will not be abused and where it will be maintained correctly.
Sweeping, damp mopping, and preventing damage from excess liquid, direct sunlight and heavy objects being dragged across the floor will equal a floor that will last. However, if the floor gets abused or neglected and the finish wears off, homogeneous cork can be sanded and refinished just like many wood floors, but heterogeneous (veneer) cork floors cannot. This is an important point, especially when floors are being specified for commercial use.
The wide majority of products today come as a pre-finished floor with a matte polyurethane coating. Sometimes cork is installed unfinished, to be stained and finished on site. Urethane finished “Old School” waxed cork is rarely specified because it needs a lot of work to maintain and there are not that many maintenance people out there any more who know how to use “real” paste wax. If you run into a waxed cork floor, (or a wood floor for that matter) you’ll need to get the right people involved to take care of it.
Flooring contractors often have initial maintenance as part of their contract, so if that is the case for a cork floor, do your homework before bidding the job. For pre-finished floors, what needs to be done depends on the intended use of the floor and the manufacturers guidelines. For example, it is recommended on many urethane floors to screen the floor and apply one or two additional coats of urethane before using the floor. This adds an extra level of protection to the floor, especially at the edges, and will also take down any high spots, edge curl, or ledging of the cork tile. Again, before starting the job, make sure all of these details are spelled out so there are no surprises.
After checking to be sure the floor is flat and properly installed, if any adhesive residue is on the surface clean it before taking the next step. Since the adhesives are water based, it’s usually not necessary to use a solvent unless it’s dried on there for a period of time. When plain water won’t take it off, use a solvent on a white cloth to remove the residue. I like denatured alcohol as opposed to mineral spirits for a solvent because it evaporates quickly so it has less lingering odor and leaves little residue behind on the floor.
The next step in initial maintenance will depend on the specification. It may just be a damp mop to clean the floor, or it could involve applying a coat or two of polyurethane, which we will cover later in “refinishing.”
An Ounce Of Prevention…
Like any resilient or wood floor, preventing damage is important. Make sure furniture has proper glides that won’t scuff or scratch the floor. I recommend replacing all the glides on chairs when a new floor gets installed. I like felt pads on the bottom of every piece of furniture because it makes the furniture easy to move and doesn’t scratch.
Use walk-off mats to keep dirt and liquid from outdoors off the floor and chair pads in any areas where rolling chairs are present. This is an important point as chair pads are often not used because of the way they look. I worked on a 55,000 square foot cork floor tile project in a health care facility that came out great, but after a few years they were unhappy with the floor in areas by desks because they didn’t use chair pads. Finally, because cork is susceptible to damage from sun like any other natural product, use window coverings to minimize fading.
For cleaning, sweep regularly and damp mop as you would for a wood floor. There are commercially available wood cleaning kits that use microfiber mops and a spray cleaner. Wet mopping is not a good idea. I have seen an auto scrubber used in commercial settings, but it needs to be the type of equipment that can clean without damaging the finish. These machines have water containment and vacuum systems that clean the surface and leave the floor dry immediately. Spray buffing may also be an option to maintain a desired gloss level, but don’t apply standard resilient floor liquid floor finishes on cork because they need to be stripped periodically and the stripping chemicals could potentially damage the cork.
A “screen and recoat” procedure similar to a wood floor is recommended on a new floor when required by spec and also on older floors once the finish starts to get a little worn. This involves lightly abrading the urethane floor surface with a sanding screen or proper buffing pad, cleaning the resulting dust and applying a coat or two of the recommended urethane finish. Don’t wait too long on those older floors, because if the finish wears off, it’s too late. I learned this the hard way in my own home and wound up having to sand and refinish the wood floors. An occasional “screen and recoat” will prevent the factory coating from wearing off and the floor can last almost forever.
If the factory coating does wear off, homogeneous cork has the color all the way through, so it can be sanded and refinished. On the other hand, heterogenous cork floors are made with veneers, so sanding would remove the design. A homogeneous floor that has been stained can still be sanded, but this will remove the color so it will have to be re-stained or just clear coated to have the natural cork color back. Regardless of which process you use, make sure the urethane finish you use is recommended for cork. Because cork is so flexible, not all finishes can be used. Some of our FCICA associate members are a good resource for these products.
* ASTM F 3008, Standard Specification for Cork Floor Tile, available from www.ASTM.com