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Cork flooring/underlayment

I'm looking into tearing some carpet out of the two bedrooms in our home, and possibly finishing the basement with cork flooring, to create a less dusty space. We have allergies and also pets. I've done some research and am leaning toward cork. I have read on some brands that the cork has an attached underlayment, there-by saving the cost of that aspect of the installation. Yet, other brands say you need to install a moisture barrier/underlayment. Do all cork flooring installations require an underlayment? Is it an optional thing?? Like, for our bedrooms I don't think a moisture barrier is necessary, but in the basement may be a good idea. Although, it might be a better idea to protect the underlying wood in the rooms, and not so with the concrete in the basement. I'm not sure, but some good advice might get me moving in the right direction.
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Posted 2011-01-10T01:40:09+0000  by Wildonetone Wildonetone

Hey Wildonetone,


I'm a Home Depot associate from the Atlanta area and I work in the flooring department at my store. You have really hit upon a very good substrate to use to replace out the old carpet. In fact,  I couldn't of picked a better surface to replace your old carpet than with cork. :manvery-happy:


Having underlayment for the cork is necessary for the flooring IF the cork is in click-lock or in plank form i.e. you are going to float the floor on top of the subfloor. I am aware there are solid (5/8" or thicker planks) pieces of cork sold in the industry, but they are not as common as the click-lock forms (5/8" or thinner). Underlayments are required for all floors that are click-lock  and plank.  Thats because it offsets the distribution of weight from everyday foot traffic regardless of it being cork or not due to the thinness of the product. Higher ended models of underlayments also give you moisture barriers (as you stated already) as well as sound reduction qualities. Also, as you stated in your question it has a  moisture barrier as well. For the basement with a concrete subfloor, having an underlayment is crucial. The reason why is that even that the slab maybe dry at times, concrete as a substrate is porous and when moisture in it needs to escape, it has nowhere to go but up. Having an underlayment with a moisture barrier prevents any damage incurred on your cork flooring. I'd hate for you to start the project over again due to inferior underlayment.  I did a post earlier on underlayments for bamboo click-lock, and the one specific underlayment I recommend is in the post if you choose a cork that doesn't have a pre-attached underlayment, here is the link:



 Consider underlayment  like this, cork (or any click-lock flooring) needs the underlayment like how we need a good sole on our shoes, it helps out with not only with comfort but with function too. The best part is, the picture of the underlayment in the post I just linked above is very reasonably priced and we sell it in-stock at our stores! 



Hope this assists you and any further questions please don't hesitate to ask!



Posted 2011-01-10T14:45:53+0000  by Joseph_HD_ATL

I know this is an old thread to be reviving, but I've got a question relating to this...


So even with a brand of cork flooring that already has a cork underlayment attached on the bottom, another foam underlayment is still necessary to lay down?


I've done a little bit of research on underlayment and wanted to find an underlayment that has some decent sound deadening characteristics for above average sound deadening.  Reason being is that I will be moving into a condo with a tenant beneath me.


I would go with the 6mm cork underlayment, but that is a bit expensive.  I have heard that regular polyethylene foam underlayment has some ok sound absorbing qualities as well and coupled with cork flooring with cork underlayment attached already, this would be the easiest way to go.  However, just in case I also want to look into something in between, that is cheaper than full on cork underlayment, but has more sound deadening qualities than regular foam underlayment.


I was looking at the following item as an alternative:


Could anybody give some opinions on using this as an underlayment for cork flooring?  In the product description it says: "Do not use if flooring being installed already has an attached underlayment".  Is there a reason for this?  Could I use this anyway?


Any other suggestions for sound deadening underlayment to use in combination with cork flooring?

Posted 2013-07-02T04:06:09+0000  by kurisu

Hello kurisu,


Welcome to the community!


First off, NEVER add more loose underlayment for any floating floor system you use than what the manufacturer calls for, even if it is pre-attached. It usually voids the warranty and is simply not needed for installation purposes.


And quite honestly, too much underlayment jeopardizes the integrity of the planks locking together. This can lead to separation and failure of the floor. This is the reason why you can't use extra underlayment.


You did pick a good underlayment for sound reduction properties. You are correct in the cork underlayment being expensive, but it has one of the best sound deadening features of any underlayment out there.


With that said, you can still use a pre-attached underlayment on your floor over a GLUED-DOWN cork underlayment. As long as the first underlayment placed down is glued directly to the subfloor, then you are okay. It's only the loose underlayment that can't be put with another.


In terms of pricing, I would opt for gluing down a 1/4" thick cork underlayment; the price isn't as steep as you think.

This maybe the 6mm you were thinking of, but it covers a large area for the entire roll (200 sq. ft.).

QEP 200 sq. ft.50 ft. x 4 ft. x 1/4 in. Roll of Cork Underlayment for Tile, Laminate and Floated or Glue-Down Wood Floors

As long as you glue down the underlayment above, you can place a cork flooring with pre-attached underlayment on top of it.


Another thing we neglected to talk about was the state of your subfloor now. Even with using sound reducing flooring and underlayments, it's equally as important to ensure your subfloor is level and secure to the floor joists.


Any squeaks or loose areas really need to be resolved before you add any new underlayment/flooring to ensure any unwanted sounds are reduced. This goes as a long way just as much as the cork and/or underlayment you use as well.


At minimum, you can use a pre-attached underlayment that comes with your floor, but do not place any added underlayment to it unless it is firmly glued down first.


I hope this information has assisted you, and let me know if you have any further questions.


Posted 2013-07-03T15:22:26+0000  by Joseph_HD_ATL

Hi Joseph,


Thanks for the reply.  That's a lot of great info.

So just to make sure, if I were to use a cork flooring piece that does not have an built in underlayment, then the use of underlayment would then be required? (in which case, the Soundbloc underlayment would be acceptable?)


That's not to say I'm not considering the 6mm cork underlayment though.  Are there any good 3mm cork underlayments that would work?  I know they are not as effective sound dampeners as the 6mm, but at the least they should be much better than laying down foam, and still work very well if I were using cork flooring with built in underlayment.  It also wouldn't raise the floor as much I would think.


About laying down the cork underlayment:  For a floating floor installation, does the underlayment still need to be glued down?  Or can it be rolled out and taped at the seams (if necessary) shortly before floor installation?


Posted 2013-07-03T19:15:25+0000  by kurisu your reply. I guess the cork underlayment must be glued down first for floating floor installation. Any tips on how to glue down?
Posted 2013-07-03T19:18:31+0000  by kurisu

It's no problem.


Yes, you will need to glue down the underlayment. Luckily, we sell an adhesive made exclusively for cork underlayments.


Click below for more information.

Roberts 7250 4-gal. Cork Underlayment Adhesive


Once you place down the cork, use a floor roller to ensure the cork adheres in a firm and uniform way.

Extendable Floor Roller

As I stated earlier, make sure the subfloor is good shape first. Once you reduce the amount of squeaks and uneven areas, you can then put down the cork underlayment. After that, you can place any floor of your choosing afterwards.


Let me know if you have any further questions.


Posted 2013-07-03T19:47:11+0000  by Joseph_HD_ATL

Thank you for the information.  Could something like 2 inch nails be used instead of the glue?  If so, what kind of nails would be recommended?

Posted 2013-07-03T21:28:22+0000  by kurisu

You are welcome. No where in the specs for this did I see that you could nail it. In fact, I would strongly recommend you NOT to do this.


Besides, gluing it down will ensure the entire surface is uniform and even, where a nail can get loose and not hold properly over time.


You can nail if you want to at your own risk, but the glue is a much better bet for you now and in the long run.



Posted 2013-07-03T21:30:42+0000  by Joseph_HD_ATL

Hello Joseph-I would like to float Pergomax 'Hampton Hickory' 8mm laminate flooring over a concrete subfloor. This particular 8mm flooring has an attached 2mm foam-type underlayment.


I have no experience with this material, but would like to reduce the possibility of this floor sounding 'clicky' or 'hollow' once it is completed.


Having said that, I was hoping to float this Pergomax (w/2mm attached foam underlay) over an additional 6mm cork underlayment.


Regrettably, Pergos instructions explicitly state not to 'stack' underlayments of any kind. Other distributors of cork underlayment have said the same thing (don't do it).


Your previous posts also warn against using additional underlayments with flooring that already has an attached foam backing, as this may lead to failure of the locking mechanism, and will definitely void any warranty.


Could you please explain why it is acceptable to float flooring with an attached underlay over a glued cork underlay, but not a loose-laid cork underlayment? Why is one method OK (glued cork), while another is prohibited (loose laid cork)?


Thank you, again.

Posted 2014-01-03T00:08:00+0000  by DrSpencer

Good morning DrSpencer,


Thanks for your question and welcome to the community!


No wonder I couldn't find your Pergo Max Hampton Hickory floor...we don't sell it!


However, I read the specs on our competitors website and yep, it does have the attached underlayment. I didn't see anything on their install guide, but you can contact Pergo directly at 1-800-33PERGO for specific information.


Since this is laminate and not cork flooring (which is why I'm not sure why you wrote on this thread vs. starting another), you may experience a 'clicky' sound as you say due to how the product is made (man made particle board core).


The sound is a combination of how well (or poorly) the floor was installed, as well as the substrate itself. Also, I can't attest or say how 'clicky' or 'hollow' your Pergo laminate will be; only you can decide this for yourself.


As stated earlier in this thread...


" you can still use a pre-attached underlayment on your floor over a GLUED-DOWN cork underlayment. As long as the first underlayment placed down is glued directly to the subfloor, then you are okay. It's only the loose underlayment that can't be put with another."


It's essentially very simple. Since lay down (no glue) underlayment can possibly shift, this can cause a chain reaction leading to the planks of the floor separating. Glue downs stay put, and don't have issues with buckling and are much less prone to failure.


Also, you will need to use an adhesive for the underlayment that is urethane-based, so that the adhesive also acts as a moisture barrier. This is essential over concrete subfloors.


At the end of the day, I'd advise you to really contact Pergo with the number above directly for your floors underlayment requirements. Laminate floors install and act very much the same as their cork floating counterparts, but it would be wiser for you to contact them directly for specific instructions.


Every brand/vendor has their own specific requirements, and I'd like you to keep you in good graces for upholding any warranty you may have with them.


Please let me know if you have any additional questions, and I hope this information has assisted you.



Posted 2014-01-04T14:58:07+0000  by Joseph_HD_ATL
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