Posted on

Installments: Cork, a guide for specification, installation, maintenance

November 10/17, 2014; Volume 28/Number 11

By Christopher Capobianco

Screen Shot 2014-11-18 at 4.24.30 PMCork tile has been around for about 100 years and is still widely used for floors and walls, especially commercially. I find it intimidates some people, but if specified, installed and maintained correctly, the result can be a beautiful, warm, quiet, environmentally friendly floor that will last for decades.

I’ve worked with cork full- time for the past 14 years, both in sales and as a technical consultant. I chaired the task group that created the brand new industry standard, ASTM F 3008, 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 students since 2002. And yes, some of my friends call me “the cork dork of New York.”

A rapidly renewable material from the Mediterranean region, cork is bark from the cork oak tree, which is harvested and regrows every nine years or so. Cork bottle stoppers are the main byproduct of the trees, while all the material that isn’t used as corks becomes a variety of other products, including floor tiles.

Classified as resilient flooring, cork acts a lot like wood flooring but has characteristics of both.

Like wood, pay attention to proper temperature conditions, acclimate material on the jobsite and don’t install cork in a space that isn’t climate controlled. Also, don’t install it in very wet or sunny spaces, and maintain cork just like wood flooring.

Similar to resilient, the substrate for cork needs to be dry, very smooth and solid, so concrete moisture testing and substrate prep are critical.

Cork tile is best installed with water-based contact adhesive applied to the tile and the substrate. I have seen countless failures where a trowel-applied adhesive was used; don’t attempt that shortcut. Contact adhesive for cork has a 25-year track record, and it works. Once you get used to it, it’s easy and has advantages—it’s applied with a paint roller so you are off your knees and it’s a dry set so the floor can be walked on immediately. Just set the tile in place, bang with a rubber mallet and it’s done. You can coat the tile a day ahead of time, so one installer can prep the substrate while the other coats the tile.

The next day, clean the floor, coat the substrate, wait 30-45 minutes for the adhesive to dry and lay the tile. Some cork manufacturers are even offering pre-coated tile, but there is concern about its shelf life. Any older product may need to be coated on the back, anyway.

Cork is manufactured as pre-finished or unfinished homogeneous (through color) tile or pre-finished heterogeneous (veneer) tile. Homogeneous can be sanded and refinished, so it gets used in a lot of high-traffic commercial spaces. I’ve seen 50- and 60-year-old floors that are still in good shape. Urethane pre-finished is the most popular option today, and additional coats of urethane are often applied right after installation. For ongoing maintenance, this same process known as “screen and recoat” can be done periodically to keep a coating of urethane on the floor and prevent wear into the cork itself.

For daily maintenance, sweep or use a damp mop with wood floor care products. Use mats to keep off dirt and grit, protect from sunlight and make sure furniture has soft felt glides.

This is just a quick overview for cork floor tile. When used, installed and maintained correctly, it’s one of the most beautiful floor coverings I have seen.