How to install a unheated space with cork flooring?

(10:35:23) Visitor 74789261: Hi, I’m leading the build of a yoga/shiatsu studio and my client would like to install a cork flooring. The building has a concrete slab and will NOT be heated permanently, as it’s off-grid in the wood in a vacation centre. Which of your product would best fit this application?
(10:35:45) *** Cacork Floor joined the chat ***
(10:35:54) Cacork Floor : A cork floating floor – 10mm or 11mm golden Beach
(10:36:24) Cacork Floor : As soon as it is “unheated” or goes without HVAC, the warranty is void – but then again so would ANY floor.
(10:36:53) Cacork Floor : In the Pacific coast region this is not much of an issue.
(10:37:10) Customer: I’m from Quebec
(10:37:11) Cacork Floor : IN more extreme areas the life of any floor will be reduced when exposed to extremes.
(10:37:57) Customer: The floor will go through temperatures from -25 to +25.
(10:38:13) Cacork Floor : Yep…reduced life expectancy = to be expected.
(10:39:34) Customer: What would be the best way to prevent damage, I’m thinking especially in terms of underglooring. I was thinking vapour barier plus foamy underlayment
(10:39:36) Cacork Floor : My shift is over – is there anything else?
(10:39:49) Cacork Floor : Please send your questions in an email
(10:39:57) Cacork Floor : Contact us
(10:40:29) Cacork Floor : The details of such an install are pretty tough to get done over a chat. It should take me 1-2 hours of typing to get it all down.
(10:40:43) Cacork Floor : Please send email with your question and I will try my best to answer tomorrow.
(10:40:55) Customer: Ok, thanks!


I happen to build a Yoga studio that’s going to be off-grid in the forest, here in Quebec. My client insists on using cork for flooring as it’s a natural, soft and “warm” material. I’m concerned because the building will be left unheated for long periods of time, so the humidity rate will fluctuate a lot. This would probably cause expansion and contraction to the floor, especially if it’s a floating floor, and could badly damage it if it happens too often or too quickly. A fireplace will be added to the room and I’m afraid that someone coming in the dead of the winter might make a fire too hot too quickly and the humidity rate would change rapidly.

The building is round, 27 feet of diameter inside. Right now the floor is a concrete slab. What would be your best product to tackle those challenges? I understand very well the fact that because humidity and heat will not be constent, your warranty will be void. I want the best option to mitigate my client needs with the conditions the building is into.

I was also considering installing a polystyrene insulation between the concrete and the cork floating floor for added insulation and protection from temperature differences between the top and the bottom of the board.

Please indicate me what solution you would recommend to me given the circumstances, and which of your product s best suited.

Cancour Floor Answer
Thank you very much for taking the time to read me and accepting the challenge.


This is one of the toughest things you will do – install “indoor” materials in an unheated space in Quebec.  Everything you install will have a limited lifespan.  Contrary to my colleague’s advice, the glue down tile is the last thing I would use in this setting.  I’m sorry but he is in training and was “guessing” when he answered your chat.

I believe I may have answered your emails in the past regarding this situation.  Regardless, the answer is “floating floor” for as long as it lasts.   Insulating the slab won’t make any difference.  Cold is cold and hot is hot.  Unconditioned spaces are still ‘unconditioned’ no matter how insulated they are.

A cork floating floor + 6mm cork underlay = a nice way to insulate the space.  This will do what the ‘polystyrene’ insulation would do without the big expense.  A cork floating floor in your situation may only have 7-15 years of life in it.  A carpet = 7-15 years of life.  Vinyl = 3-7 years.  Laminate = 3-10 years.  Linoleum = 5-15 years.  Hardwood = 5-15 years.  As you can see, everything we have that is “interior” grade is going to have a vastly shorter life span.  The cork floating floor will function nicely while it is structurally sound.  Once it starts to deteriorate, it will do so very quickly.  The joints will show gapping, the boards will feel “spongy” like they are too damp/wet, etc.

A floating floor will do better than a permanent/glued floor.  It will have the chance to EXPAND when too hot/humid (that’s fine) or contract when it is too cold.  As long as it has the SPACE to expand/contract, it is fine.  The lifespan is greatly disturbed.  You *might get 10 years out of it.  You *might get 25 years.  You might only get 5 years if moisture intrusion (roof is compromised, flooding, etc) occurs.

Personally I would put in the entry level Golden Beach + cork underlay so that when the fire is lit, the space heats QUICKLY and maintains heat for LONGER.  It doesn’t make much sense to pay $2/sf more for a pretty pattern when it has the same “life span” as the entry level Golden Beach for $2.49/sf.  The choice is yours.