Eco-Friendly Cork Flooring: A Comprehensive Guide

Cork flooring is the perfect alternative if you are environmentally conscious and believe in using renewable resources in your living spaces. This type of flooring, which is made of natural and renewable ingredients is an environmentally conscious choice for your interior decor project, but they are also versatile, sustainable, and costs about the same as hardwood floors.

Cork floors are also soft but firm to the touch and are good for your back and knees as it helps you relax.

In this article, we have described what is cork flooring and why it is a great choice for your home.

What is a Cork?

What is Cork

Cork is a natural plant tissue that is lightweight and water-resistant and used commercially as stoppers and for insulation. Its microscopic honeycomb cell structure contains gas that is 90% air, giving it properties of insulation and resilience.

Where does Cork Come From?

Cork Origin

Barks of the cork oak trees are used to produce cork. Once the tree reaches maturity (around 25 years), its thick barks are cut by hand in a harmless process called uncorking. A cork oak tree can live up to 250 years and one tree can be uncorked only once in nine to ten years. In fact, “THE 9 YEARS LAW” formulated in 1930 aimed to protect the Cork Oak tree. As per this law, it is mandatory to maintain an interval of a minimum of nine years to harvest the tree. Further, one could harvest only after the tree reached a minimum girth of 60 cm. As per the study, the tree could be harvested for the first time after it reached the age of 25 years.

After extracting the barks, the inner portion and the rough exterior are separated. The barks are then ground into different-sized granules. It is mixed with binders, turned into blocks, baked, and cut into tiles, sheets, or veneers to be used in the manufacture of cork flooring. Cork flooring is mainly manufactured from waste of the cork wine manufacturing process and therefore, cork flooring is regarded as a recycled product.

Now let’s understand the pros and cons of cork flooring in detail.

Benefits of Cork Flooring

Benefits of Cork Flooring
  • Sound Absorption: Cork has superior acoustic and sound-absorbing properties, making it quieter to walk on than other flooring materials like laminate, vinyl, and wood. It also reduces the impact sound of an object dropping on the floor.
  • Insulation: Cork is able to stay at room temperature, making it warm and comfortable to the touch. It is also unaffected by extreme temperatures because of the air cells in its structure. Its heat absorption properties make it a good choice for your children’s bedroom and playroom and also reduce heating costs in the colder months.
  • Resistant to Mold, Insect, and Fire: Cork, when properly sealed, is known to be fire-retardant and resistant to moisture, rot, and wood-boring bugs. This is because the material contains an antimicrobial wax – suberin – that repels bugs, mold, fire, and moisture.
  • Easy to Clean and Maintain: You can maintain your cork floor with just a regular vacuum, sweeping, and a damp mop or cloth. However, felt pads on the legs of your furniture will help you cork floors last longer.
  • Hypoallergenic: This material has natural properties that make it resistant to mildew and insects. It is also anti-allergenic.
  • Healthy: Cork doesn’t release any toxic gas or micro-fibers, which makes it healthy for children, adults, and pets.
  • Shock-absorbing: Cork’s natural cellular structure gives it shock-absorbing properties. This is why cork kitchen floorings are the best for standing and for preventing falling dishes and glasses from breaking.
  • Environmentally-friendly: As mentioned before in this article, harvesting cork from cork oak trees is a sustainable process. Trees are uncorked in intervals of about a decade over the lifetime of the tree, which is around 250 years. It is the most eco-friendly flooring material available.
  • Easy Installation: Cork is available in standard forms like planks and tiles that are easy to install in your home. It is easier to install than glue-down tiles and most hardwood flooring.
  • Non-slip: The cork floor remains a safe place for your feet even when wet. There is no risk of slipping on a cork surface.

Drawbacks of Cork Flooring

Drawbacks of Cork Flooring
  • Fades in Direct Sunlight: Cork floors will lighten after prolonged exposure to the sun and UV light. It is best to avoid cork floors in areas that receive a lot of direct sunlight unless you have coated the cork with UV protectants and have UV-blocking film on your windows.
  • Not Scratch-Proof: Over time, cork floors can get scratched and dented, especially if you have pets living indoors. The fact that cork offers bounce means that the material can be dented by heavy furniture. Use furniture pads on your furniture legs to prevent damage to your floor and move heavy furniture around with care. You can refresh the topcoat of the cork flooring periodically or avoid putting cork floors in high-traffic areas entirely.
  • Periodical Resealing: You will be in for a bad time if water manages to get into the cork through dents or scratches. This is why you need to properly seal it with polyurethane or a wax product. You will also need to reseal or refinish the floor periodically as faded or improperly sealed cork is easily damaged.

Types of Cork Flooring

01. Cork Tiles

Cork Tiles

There are four types of installation-ready cork tiles. The first is unfinished, stained, and ready-to-urethane. They come in the form of tiles and need three to four coats of low satin urethane. These square or bevelled-edged tiles are semi-smooth and have a visible natural texture. Before laying down cork floor tiles, you will need to apply adhesive to the subfloor.

The second type of cork floor product has a natural, unfinished surface and needs three to four coats of urethane for sealing. While these tiles come with a pre-glued back, you will need to apply adhesive to the subfloor before installation.

The third type comes pre-finished with many coats of urethane. They are only available in square-edge style and have a pre-glued back, although you will need to apply adhesive to the subfloor before installation.

The fourth is also a pre-finished variety, but with vinyl. Here, the cork’s surface is infused with vinyl and sealed with an acrylic lacquer that prevents the seepage of moisture. This cork product has a smooth surface with a low gloss finish and doesn’t come with a pre-glued back. As an option, you can put a cork dressing on the vinyl surface, which will give it extra protection and make cleaning easier.

Generally, cork tiles are glued to a subfloor. However, many manufacturers these days offer peel-and-stick tiles that are less messy and stressful to install. These peel-and-stick tiles are perfect for DIY enthusiasts and come in different colours, sizes, and styles.

02. Cork Planks

Cork Planks

Unlike cork tiles, cork planks don’t need nailing or gluing to the subfloor. They come with a tongue-and-groove joint that enables you to link one plank with the next. To keep the planks in place, you only need to apply glue in the groove and on the end sides of the plank and push them together with a knocking block.

The construction of a cork plank or panel varies between manufacturers, but the general composition is as follows:

  • Underlayment: Sometimes installed separately, this is a low-density, flexible cork material that provides acoustic insulation.
  • Stabilizing Core: This part of the plank has the tongue and groove joint that will help one plank interlock with the other. It is made of either high-density fiberboard (HDF) or medium-density fiberboard (MDF).
  • Cork Core: The purpose of this component is to provide additional impact absorption, comfort, and insulation. However, not all cork flooring manufacturers include it in their products.
  • Top Layer/Cork Bark Veneer: This is the visible layer of the cork floor. It can either be the veneer of the cork tree bark or the cork that has a certain texture or pattern.
  • Wear Surface: This is a UV-hardened sealer (varnish, oil, or other) applied either at the factory or in the field.

03. Cork Sheets or Rolls

Cork Sheet or Rolls

Cork flooring also comes in the form of sheets or rolls and is used in commercial spaces. While cork sheets come in specific sizes, rolls are cut to the size of your preference. They are used as an underlayment to level out uneven subfloor heights across rooms, add extra insulation, and provide soundproofing.

Tools Needed for Installation of Cork Floors

Tools for Cork Floor Installation

Here are some tools you will need to install a cork floor:

  • Tape measure
  • Chalk line
  • Table saw
  • Spacers
  • Pencil
  • 6-millimeter film polyethylene
  • Polyurethane cleaner
  • Cork floor squares or planks
  • Adhesive glue
  • Knocking block of wood

These are some optional items you may need when installing a cork floor (depending on the cork product):

  • Low gloss polyurethane sealant
  • Sub-floor adhesive and applicator
  • 100-pound floor roller

Preparation of Sub-Floor Before Installation

You can lay cork flooring over two types of sub-floors: concrete and plywood.

01. Concrete

You can install cork floors on concrete subfloors of any grade (below, above, or grade level). The concrete sub-floor must be clean, smooth, and at least 1/4 inch thick. You can level out any low areas with levelling compound or screed and grade down high areas. Once the levelling and filling substances have dried, cover the surface with 6mm polyethylene sheets. You can overlap and tape together the sheets at the seams for a minimum of eight inches to ensure that there is a tight moisture barrier.

02. Plywood

The process of laying cork floors over plywood is pretty much the same as laying them over concrete. Just ensure that the sub-floor is smooth, level, and clean. Fill in holes and low areas with wood fill and sand down high areas of the floor. Check for moisture content once the wood filler has dried.

Installing Cork Flooring

Installing Cork Flooring

Cork floors are simple and cost-effective. Installing it is easy once you know the right techniques.

Things to Keep in Mind Before Installing Cork Floors

  • As cork is a natural floor product, it will have to be acclimated before installation. Remove the flooring material from the wrapping and then place it in the room where it will be installed for at least 72 hours. Ensure that the heat, humidity, or air conditioning levels are consistent with the normal room conditions so that the cork can reach the same temperature and humidity levels during this period.
  • Cork has a similar expansion rate as wood in humid conditions. High humidity (like in the summer) will cause minor expansion, and dry or low humidity (like in the winter) will cause minor contraction.
  • If the moisture content of the room is above 14%, install polyethylene sheets over plywood before you lay the cork floor. Install a moisture barrier if the room you are working in is over a crawl space or slab.
  • Use a table saw with a fine-toothed blade to cut the cork. When cutting cork, place the decorative side of the plank or sheet face down to avoid chipping or splitting the finished surface.
  • Cork is a porous material. It will absorb primer, water, or any liquid if not sealed properly. Don’t place any wet objects on the floor until the sealant has dried. Also, allow the primer on the subfloor to set and dry before laying down the cork flooring so that it won’t absorb the primer and distort.
  • Cork, like most natural flooring materials, can vary in colour and pattern.

Installing Cork Tiles

Installing Cork Tiles

Start by removing any existing moldings and transitions from around the room. Cork floor tiles need a primed subfloor before installation, called the glued-down method. You should use a natural and water-based primer, regardless of the type of subfloor. Apply a thin layer of primer to the whole surface with a short-nap roller. Wait for the primer to dry completely before applying adhesive to the subfloor; this should take about 45 minutes under normal humidity and temperatures.

In the same way, apply a coat of the adhesive to a 50-square-foot area at a time. You will know you have applied a sufficient amount of adhesive if the coat appears consistent and glossy. The adhesive layer will take about 20 to 30 minutes to dry. Install the cork tiles within an hour of applying the adhesive. Apply a second coat of adhesive if the subfloor is too porous.

Mix a minimum of three boxes of cork floor tiles for the best mix of colour and pattern, and install them in a staggered joint pattern. Allow gaps of about ¼ inch for expansion, and use spacers around the room to maintain consistency.

Note: A spacer is an object of a certain thickness made of plastic, wood, or ceramic. It helps you keep a consistent distance between tiles or between the wall and your laminate, cork, or other flooring material. They come in different sizes, but the most commonly used ones range from ¼ to ⅜ of an inch.

About ¼ inch away from the perimeter walls, mark a chalk line and lay the tiles piece by piece, row by row. These tiles generally come pre-glued and will quickly adhere to the subfloor, so you will need to place them carefully. Be sure to place the cork floor tiles beside one another and gently tap them together for a secure seam. There is no need to firmly press the tiles together, as there should be some room for them to expand naturally.

Once you’ve finished laying the cork flooring, use a 100-pound or 40 to 50 kg floor roller to roll the cork several times in several directions. Allow the cork to set overnight, and roll the floor again multiple times in all directions before applying a sealer (for unfinished tiles). Apply at least three coats of sealer for residential cork floors and four coats for commercial floors.

Once you have rolled the floor for the final time, let it set for a minimum of 24 hours before you start using the newly laid cork floor. Wipe off any excess glue on the floor’s surface with a rag dampened with mineral spirits, and then reinstall the molding and transitions, if any.

Installing Cork Planks

Installing Cork Planks

Planks don’t need to be glued to the subfloor as they stay down due to their own weight and are held together by a tongue-and-groove mechanism. The use of these planks is called a floating cork flooring installation.

Before you start laying the planks down, remove any moldings and transitions from the room. Locate the longest wall that will be parallel to your planks and make a chalk line ½ inch away from the wall around the perimeter. The chalk line will set your line for the first row of planks and the ½-inch gap allows for expansion of the flooring material.

Note: If you have boxes of planks that vary in colour, mix them up so you have a nice blend of colour patterns across the room.

Start laying the planks down (groove sides towards the wall) from the left side of the room to the right. Place two spacers per plank, ½ inch from the wall, while keeping the planks in line with the chalk line. The spacers will keep the first row of planks from moving as you lay down the second row.

Place the planks in a staggered pattern and make sure that none of the joints align with another. Measure, cut, and number the planks in the order they will be used. Once your materials are ready to use, apply glue to the inside of the groove and the short ends, where they will be in contact with other planks.

Don’t apply glue to the tongue of the planks when laying down the second row, and use only a knocking block to gently tap the planks together. Continue to lay the planks row by row until you reach the other wall. You may need to cut the planks lengthwise when you reach the last row. Use the chalk line as a guide to cut the planks.

Remove the spacers along the walls once the glue between the planks has been set for at least 24 hours. Wipe off any glue from the surface of the floor with a rag soaked in mineral spirits.

Note:  Whether you are installing cork planks or tiles, apply an extra water-based polyurethane sealant. An extra coat of sealant will enhance the appearance of your floor and protect the joints from seepage.

Installing Cork Sheets as an Underlayment

Installing Cork Sheet

Cork sheets and rolls are used as an underlayment. The first step is to leave the sheets and rolls in the room in which they will be laid for at least 72 hours to acclimatise to the room’s natural temperature and humidity.

Make sure that the floor is clean, dry, and smooth. The surface should be free of any bumps, projections, holes, oils, grease, sealers, and other contaminants. Make sure that you level out the floor if there are any low or high areas.

If you are using cork sheets, they will come as ready-to-use panels. If you are using a cork roll, you can measure the room and cut up the roll accordingly. Lay the underlayment loosely over the area and make sure that both ends of the roll curl down towards the subfloor. Pull back half of the roll you just laid down and apply adhesive to the subfloor. Return the roll slowly back into position and use a 100-pound or 40 to 50 kg roller to roll the section in both directions. Repeat the procedure on the other half of the roll and use the same method till you have laid the whole floor. Ensure that the joints are tightly butted together, and leave 1/2 inch between the walls and the cork for expansion. Also, let the adhesive set (read the adhesive manufacturer’s instructions for the set time) before laying any additional flooring.

Cork Flooring for Basements

Cork Flooring for Basement

There are three general types of basement situations:

  1. Unfinished basement- This is the first stage where the basement has only a concrete slab. It may or may not be damp.
  2. Semi-finished Basement- This is the second stage where the concrete is sealed and the humidity is under control.
  3. Finished Basement- This is the final and ideal stage where the basement is fully renovated and you have installed the drainage systems (interior or exterior) to eliminate any further moisture problems.

Most homes have semi-finished basements with treated walls, a sealed floor, and provisions for ventilation. They have a built-in vapour barrier under the basement slab, preventing moisture from moving up from the ground. So, there shouldn’t be much moisture in the basement after the concrete has had six months to cure, making it safe to install the flooring. You can check the moisture levels inside the basement with a moisture meter.

If your basement has high moisture levels, it can mean that there is poor drainage around the foundation. Try to fix the issue before installing cork flooring. Although cork is water-resistant, there is no such thing as waterproof cork flooring. So, the cork should “float” over the basement floor rather than being glued, allowing the moisture to travel through the cork without leading to mold.

Check the cork floor packaging to see if it is suitable for installation in a basement. Most cork floor manufacturers today allow for the installation of their products in basements. They offer specific instructions regarding acceptable hydrostatic pressure levels.

The best type of cork flooring for basements is the cork plank, as it can be installed with a 6-millimeter polyurethane film. You can always use a moisture-resistant subfloor or underlayment if you want to use cork floor tiles or extra moisture protection.

How to Maintain Cork Floors?

Maintaining Cork Floors

Cork floors require only periodic sweeping, vacuuming, and mopping with a damp cloth or mop to keep them clean. Ensure that the surface of the floor is free of grit, sand, or other abrasives.

You can sweep or vacuum the cork floor weekly and mop it monthly. Be careful not to use a lot of water. Use a PH-balanced detergent or mild soap when mopping the floors with a damp cloth. Avoid harsh cleaners like oil, abrasives, or ammonia-based cleaning products on the floor. Use cleaning products approved by the cork flooring manufacturers.

Quality Check for Cork Floor Materials

Certification of Cork
  • Cork sourced from the Mediterranean is the best cork flooring material as it is more resilient than others.
  • Check for independent certifications like GreenGuard Gold and Global GreenTag if you want cork that won’t release VOCs or has no formaldehyde.
  • Choose cork flooring with the thickest wear layer as it is more durable. You can compare the spec sheets of each product to learn about the thickness of the wear layer, veneer, or top layer.

In conclusion, cork flooring is one of the best flooring materials available, as it is not only resilient but also eco-friendly, economical, simple to install, and compatible with most interior design styles. Just make sure that the cork is sealed well and that you get professional help to lay the cork floor.

Image Courtesy: Image 7, Image 9(a), Image 9(b), Image 9(c), Image 10, Image 11, Image 12, Image 13, Image 14, Image 15, Image 16

Author Bio

Andrea Noronha – Andrea Noronha is a content writer and editor with over 4 years of experience. Although she comes from a finance background, Andrea is passionate about blogging about interior design. Her other interests include travelling, baking, and digital marketing.

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