Cork underlayment + polyethylene sheeting = most cost effective insulator on the market.

Subject: Cork flooring in a basement (with subfloor panels)

Message Body: Hello, I’m currently renovating my basement (approx 1400 sq. ft.), and am looking into different flooring options, one of which is cork flooring. I read the FAQ on your website regarding basements and using a vapor/moisture barrier on the floor, but I wanted to know if it is a suitable option to use an engineered subfloor panel (Home Depot link: https://www.homedepot.ca/en/home/p.2-ft-x-2-ft-engineered-subfloor-panel-system.1000112986.html). They are particle board with plastic moisture barrier underneath. I would likely still use a clear plastic moisture barrier on the concrete floor, followed by the subfloor panels, followed by cork underlay and finally the cork tiles or floating system.

Could you please let me know if this seems logical or if there are some other concerns or potential hazards? I like the look, feel and insulation value that the cork floor provides but am concerned about the possibility of moisture affecting the performance of the cork.

Thank you, Braden Deane

Answered by Cancork Floor:

Dear Customer,

We’ve received your flooring sample order and will ship that tonight with Canada Post. In your situation, I would “skip” the subfloor system. The cork underlay + polyethylene sheeting = most cost effective insulator on the market. The Dricore product you show is a “nice” product for a high price ($1.75/sf). Cost of installation for the panels will have to be calculated as well (some guys charge as much as $1.50/sf to put these down). Your square footage indicates you would need 350+ panels ($2446.50 for exactly 350 panels). Typically you will need 10% – 15% waste for the DriCore (ad another 35 – 40 panels to that number). And as you’ve discovered, you still need the polyethylene sheeting for the DriCore. The polysheeting is the moisture barrier. It is “industry standard” and will do everything you need it to do. In fact, that is the only moisture requirement we have in a basement.

I propose the 6mm cork underlay ($0.95/sf) + poly sheeting ($0.06/sf) and red duct tape ($9.99/roll) = a beautifully insulated basement for $0.90/sf. Add the cork floating floor and you are done. If you insist on having a HEAVY DUTY insulator, our 12mm cork underlay ($1.79/sf) is cheaper and faster to install than the DriCore and would provide double or even triple the insulation the Dricore would offer.

Personally I’ve seen 6mm cork underlay + cork floating flooring offer a 7 Celsius increase in temperature in a cold basement. The 12mm cork underlay + 11mm floating floor will raise the temperature in the basement by 12 – 15 deg. Celsius.

A glue down tile is not allowed in a basement. The warranty is void. Even if you use Dricore (and do everything right), you still can’t glue the cork tiles into place. The OSB surface on the DriCore will not allow the glue to “stick”. You would be forced to add MORE sheathing (subfloor grade 3/8” plywood) to the DriCore ($1.50/sf + screws + cost of install/time). And we still wouldn’t offer a warranty due to “improper installation”.

Your situation is unique to all others that have come before you. Ask yourself if “7 celsius” increase in temperature in your basement is “good enough” for you. If it is, then the 6mm cork underlay will be just fine. If you desperately need added warmth (because you can’t get the temp above 12 C without rerouting the entire heating system) then the 12mm cork underlay would be the next step. You can do away with the DriCore subfloor system. You don’t need it if you are using cork + cork. But then again, I’m biased J

Please let me know if there is anything else I can help with.
Best regard

Cancork Floor Inc