Cork flooring was popular decades ago and is again picking up steam as a comfortable, stylish flooring option for the home. These durable floors consist of renewable materials, and installation can be an easy DIY project. Cork in thin sheet form serves as an underlayment for laminate and some types of hardwood flooring.
What Is Cork Flooring?
According to the National Wood Flooring Association, cork originates from the bark of cork oak trees native to Spain and Portugal. The trees must be at least 25 years old before harvesting, at which point harvests can safely take place every nine years. Cork trees live approximately 150 to 200 years, but some can live up to 800 years. The color of cork varies, as does its grain pattern.
Cork is naturally insulating in terms of acoustics and temperatures and is comfortable for both people and pets, as it "gives" when compressed. It comes in a variety of styles, patterns and colors, all of which penetrate deep into the material even as the floor wears over time. With continued and proper maintenance, it can retain its look and durability for over 40 years.
How Is Cork Made?
During the summer months, extractors harvest cork by chopping it from bark already loosening from the cork oak tree without harming the tree itself. The stripped bark is then left to the elements to chemically transform in wind, rain and sunlight for six months. After that time, a steam process removes contaminants, bugs and the outside layer of bark. Then, after three more weeks of storage, the harvested cork is ready for use.
After the creation of various smaller products — from wine corks and coasters to cork boards — the remaining cork becomes flooring. Manufacturers bond bark fragments together to create cork floors and cut the materials into many sizes, shapes and thicknesses. It generally comes in two finishes: polyurethane or water-based, both of which have benefits. Polyurethane finishes are known for their durability and are cheaper, while water-based finishes, which are more environmentally friendly and less likely to yellow from light exposure, are more expensive. It can come as finished or unfinished.
Cork Floor Preparation
Get the room's square footage by multiplying its width to its length using a tape measure. As an example, if your room is 12 x 12 feet, it would be 144 square feet. When shopping, you can determine the amount you'll need by dividing the square footage of the room into the amount listed on the packaging. Purchase a few extra cases of what you'll need to cover the floor, as you may require them during installation.
Next, let the cork acclimatize for optimal moisture. Cork is a wood product and therefore expands and contracts with changes in temperature and humidity. Remove it from the packaging and let it sit for 24 to 48 hours in the room where it will be installed so that it can acclimatize to its surroundings.
Remove existing baseboards before installation and check the length of the door molding by propping a piece of cork underneath. If it's too tight of a fit, use a backsaw or pullsaw to trim the door casings with the plank or tile as your guide.
Check and Repair the Subfloor
Place cork over a smooth, flat surface. Do not place it over an existing wood, vinyl or linoleum floor without a plywood underlayment that is at least 1/4 inch thick. If there are several layers, tear them out before installation.
If those layers date back to the 1980s or prior, however, there may be asbestos in them, according to the Environmental Protection Agency. Do not attempt to remove old floors yourself without testing from a licensed asbestos abatement contractor who will safely remove materials containing asbestos from your home if it is present.
If you have a concrete floor, you can place cork directly over it. It must be free of dirt, oil, grease, paint or any other imperfections. Check with a professional for specific tips on gluing cork to a concrete subfloor.
Prepare and Install the Underlayment
Before laying a new floor, leave a 1/2-inch space around the perimeter of the room before any installation occurs. Build underlayment by cutting plywood to the size of the room and screw it to the existing floor. As you screw it into the floor, set the screws flush with or below the surface of the plywood. Stagger the plywood joints by 32 inches and leave gaps of 1/16 to 1/8 inch between sheets. Screw down the seams every 4 inches at the seams and every 6 inches elsewhere.
Fill and sand the seams and depressions in the subflooring with a Portland cement-based floor leveler. After it dries, scrape or sand the remainder of the leveler smooth with a pole sander and 100-grit sandpaper. After sanding, drag the blade of your scraper across the floor. If it catches on a screw, twist it lower into the plywood.
How to Install Glue-Down Cork Tiles
- Determine the center of the room by drawing chalk lines on the subfloor. Divide the room in equal quarters, measuring the number of tiles you'll need.
- Lay out tiles beginning at those lines to better see their configuration, marking where they go. Place the first tile close to the door, making sure to center it to the middle of the doorway.
- Once you know how many cork tiles you'll use, roll adhesive on them the night before placing them on the subfloor.
- Before installation the next day, make sure there is proper ventilation in the room and then spread glue on the subfloor one quadrant at a time.
- Brush glue an inch beyond each quadrant so there's enough underneath the boards.
- Glue the tiles to the floor. Once they are in place, they are hard to remove, so follow the layout precisely. If you've laid a tile by error, you'll need to pull it up with a scraper or utility knife.
- Roll each quadrant with a low-nap roller to smooth out the tiles before moving on to the next quadrant.
- Once installation is complete, tap the floor with a rubber mallet and a floor roller to bind the tiles equally across the subfloor and flatten any high spots.
How to Install Cork Planks
- Lay pieces along the longest wall in the room, measuring the distance between two walls minus the inch left for the expansion gap.
- Divide the width of the room by that of a cork plank to know what you'll need to cover the floor.
- Install the first course by pushing two pieces together, lifting one of the pieces off the floor at an angle.
- Slide one end into the other by pressing down until they click together.
- Place 1/2-inch spacers against the wall and push the floor planks tight against them, with the groove side facing out. Keep doing this until the first row is complete.
- Install the next row by clicking them into the previous pieces, tapping them in with a mallet and tapping block. Continue until you've filled the room. Weigh down what you have already installed. This is a floating floor, so it doesn't move as you go.
- Pieces may need to be cut to fit the room. Use a jigsaw with a clamped straightedge to cut them to the proper length.
- If the last course is less than half the width of the other courses, you'll need to cut the pieces in both the first and last courses to create balance on each side of the room. To measure how it will balance, add the current width of the last row to the full width of a plank. Divide that number in half to get the recalculated widths of the first and last rows and use a jigsaw to cut the pieces to that width.