Now that I pretty much suck when it comes to serious house-building projects, I’ve been given the task of researching cork flooring. Although the upstairs unit of our house is basically finished, we’re far behind schedule in terms of building out the downstairs unit. We’re so happy with our upstairs, that although our initial plan was to rent it out as a vacation rental, we’re now more inclined to keep it for ourselves, and rent out the downstairs when that is finished. This post is really more for me, but if you’re interested in cork flooring, then by all means…
What we’re looking for
As a rental property qualities like durability, and easy maintenance are key. Most landlords in the area have stories of renters who are careless or downright abusive of their homes. On the other hand, a beautiful home with a rustic feel is a huge draw for renters in the first place, so a natural woodsy feel is a big plus. The downstairs unit is built directly on a cement slab, and we want a solution that will provide decent insulation and keep feet from freezing on a cold floor. If we’d planned ahead, we would have left more room for floor insulation, but since we didn’t, we will need to be a bit more creative. Oh yeah, and it can’t cost a fortune, because haven’t exactly got a fortune to spend on it.
Durability and Maintenance
Durability is a relative sort of thing, and it can be hard to tell from different reports just how durable this flooring is. Some sites like this , claim that cork won’t stand up to wear by pets or even stilettos, and will "stand up to ‘normal wear and tear’ for only 5 -10 years. After which it will need a new coat of poly." Which doesn’t sound like that much – until I think back on how fast the last 5 or even 10 years have gone, by. On the other hand, other sites note that some cork floors installed in the early 1900s by Frank Lloyd Wright continue to boast their original cork floors. And still others claim "churches and libraries from the 1800s still boast their original cork flooring". However, I’m guessing that these long-lived floors are not the modern, easy-to-install, floating cork floors that are so popular today. What exactly is the difference?
As with a wood floor, a certain amount of regular, if not exactly frequent, maintenance will be required to keep our floor looking good. Everyone talks about additional coats of polyurethane that will help to protect the floor.
Because cork naturally gives, heavy pieces of furniture can leave long-lasting or permanent dents in the floor, and coasters are recommended beneath sofa legs, for example.
Cork changes color when exposed to UV. I’m not sure if this is any more prominent than the way that fabrics fade, but a number of places warn that if you place a large area rug on the floor, after several years, you will be able to see a difference in the color of the flooring.
Like wood floors, cork flooring is a time-tested flooring material that has seen use in many beautiful public areas. Cork is more resistant than wood floors in terms of denting because of it’s ability to spring back into shape. A thick cork floor can be sanded and refinished just like wood can be.
Cork’s natural properties makes it mold, moisture and insect resistant.
Many homeowners who have cork floors around 3-4 years old continue to sing the praises of cork, including some with large 100-lb. dogs.
Health and Environment considerations
This isn’t exactly one of our fundamental requirements, but it is nice to know that cork is a renewable resource. The material comes from cork oak trees which can be harvested every 9 years with no damage to the tree. It has very little if any off-gassing, and is sometimes made from remnants of wine bottle cork creation, so it’s not only renewable, but can also be a reclaimed resource . It has a natural waxy component, suberin, which is naturally anti-microbial, fire-resistant, as well as moisture and insect resistant, making it less troublesome for people affected by mold, or animal allergies.
I haven’t found R values yet, for cork flooring itself, but cork can also be used as an underlayment. In this role, the R Value of cork varies a great deal. One site gives an R value of 3.1/inch, while wecork.com says that their Soundless cork underlayment is 2.6 for a 1/4 inch. This seems roughly equivalent to the numbers that I found for the insulation provided by carpet pads and carpeting . However, unlike carpeting, cork does give a really pleasant woody feel to a home, and is more appropriate for kitchen/dining areas.
Wood flooring $3/sq ft.? Here’s one quote for a floating cork flooring that is only $2.79/sf . As always, I’m sure the old adage applies – you get what you pay for.
Other resources I came across
http://www.wecork.com/corkinfo.html – these guys are kinda geeky about their cork, which makes them a great reference. I like their page on exactly what the process is for obtaining and processing the cork. Plus they have a cork underlayment, "Soundless", which has an R value of 2.6 for 1/4 inch. Soundless+ is 1/2 inch thick, as well as both cork tiles and floating floors.
http://www.naturalcork.com/ – kind of a nice FAQ about cork, but still lacking the numbers that I was looking for. Prettier, but less informative than wecork.com.
Insulating concrete floors in heated basements may be hard to justify economically, but it can increase the comfort level considerably. A carpet with a thick pad helps, but it is more effective to build an insulated subfloor or sleeper floor. Before insulating, check for moisture by taping square pieces of polyethylene plastic at several locations on the floor. If a damp spot occurs within 24 hours, the floor is too moist. If dry, begin by placing a polyethylene moisture barrier down, then frame and insulate a subfloor with rigid foam or batts. Shim as necessary for a level surface. Add a second poly layer for an air/vapor barrier, then add plywood sheeting and the finish floor covering.