Cork underlay does NOT have the structural integrity needed to be used as flooring. I'm a cork expert. One of 4 or 5 in N.America. I've seen people try this cheap option. It just costs more in the end.

You are asking for a product that doesn't exist or if it did it would retail for $18-$20/sf.

Go for 100sf of cheap $2/sf cork floating flooring and install it. Put a wood frame around it (to keep it from walking itself apart) and have fun.

Rubber FLOORING is deathly expensive. $12/sf. Rubber workout mats are not flooring. The are mats. And they are heavy (75 lbs) and expensive ($75-$150 each).

If the foam mats works and you do NOT want to spend more for this project, then I think you should stick with what you know works for you.

@SJ McCarthy Thank you for the feedback, I was hoping you might chime in.

I have a few samples of floating cork plank flooring from iCork, and all of it has a feel and texture more like a wood floor. I’m wanting something that is gripper and less smooth. The samples of cork underlayment they sent are the perfect feel for what I want. And the 1/2” stuff seems pretty robust. Can you explain a bit more what you mean when you say the underlayment doesn’t have the structural integrity needed to be flooring? Would it be any worse than the foam tiles we were using before? Any other options for cork flooring that might give us more the feel we are looking for?

Also, can you explain a little more what you mean about the difference between rubber flooring and rubber mats? We were considering something like this:

https://www.rubberflooringinc.com/rubber-roll/heavy-duty-roll.html

Our last house we just laid the foam tiles over our finished concrete in a small area of a larger space. In this house we will have a room that is dedicated to the workout space and will need approx. 300 sf of wall to wall flooring. We aren’t necessarily looking for the cheapest option, but of course budget always plays a role somewhat.

OK...the 'wood look' cork options you chose = photograph of wood. If you want grippier, then go with the natural look of cork...not something that has a photograph on it. Whatever you choose, go with natural cork. Can you load photos of what samples you picked? I can tell which one's they are just by the photos...and I'll tell you more about them (I worked with iCork for years...so I've got their stuff down!).

The rubber you are looking at in the link = rubberized work out mats...in a roll format. They MUST BE a MINIMUM of 15ft long x 4ft wide to purchase. That's going to be 200+ pounds per roll.

Now to the issue of ODOUR....Did you click on the link for 'Clean Rubber' on the page you listed? Zoinks!

Rubber Flooring Safety: 5 Questions - Flooring Inc

Here's where your questions are answered....and here's what they say (direct from the link I gave = the manufacturer's OWN RECOMMENDATIONS...ahem....listen carefully to THEIR ADVICE):

Close to the TOP of the Blog, they say THIS:

Natural Rubber

Natural rubber is created by using the sap of rubber trees, known as Hevea Brasiliensis. This sap is also known as latex.

As you may be aware, latex allergies are fairly common, so a natural rubber product is actually not safe for everyone. If you’re using a rubber product in a location that might expose others to the material, it’s best to stick to synthetic rubber.

in the last third of the document here is the answer YOU NEED TO KNOW:

Is it Safe?

If you’re installing rubber in an enclosed space with poor ventilation, then off-gassing can create an uncomfortable environment, especially for people with breathing sensitivities, such as asthma. If you don’t want to deal with off-gassing, then you can purchase our virgin rubber tiles, which don’t really off-gas.

Ouch! And here are the PRICES for Virgin Rubber tiles:

Search Results (rubberflooringinc.com)

Boom! We START at $12/sf (ouch...can't...breathe....must...get...help....;-) OK...I took some comedic license with that last comment...but you get the idea.

Your 300sf is considered 'enclosed space with poor ventilation'. The roll you are looking at is going to STINK to high-heaven.

And I, or someone like me, would NEVER be able to spend time in a home with this type of flooring in it. Regardless of where it is, my LATEX ALLERGY would cause a VERY dangerous reaction = ambulance + ER visit + medication + off work for 14-30 days because of inflamed lungs (I won't get into the idea of pneumonia...I'm not that cruel).

Latex is AIR BORNE. If you get contact dermatitis from it you can have LUNG tissue inflammation (the 'itis' on the end of words just means 'swelling of'). And that gets dangerous.

I've worked out in situations with this cr@p and I had to leave inside of 10 minutes. Thankfully the MEDICAL DISCHARGE papers got me out of the gym membership.

If you want this stuff, and you are afraid of the smell, go ahead and order samples...and then put the samples close to your nose (put it on a string and wear it around your neck....nope....not kidding) and see how you like the effects. Super easy and you can do it without leaving your home.

@SJ McCarthy thanks. They sent me samples of “Sisal” and “Latte“. I agree, the wood-look one (Latte) is definitely not what I‘m looking for. The “Sisal” is a little better, but still pretty much feels like a wood floor. This may be TMI, but I like to workout barefoot (think weights and crossfit type stuff). I don’t want a hard, “cold” feeling floor (we have radiant heat in the concrete so it won’t actually be cold). I also want the flooring to have a little give, and the cork flooring samples don’t seem to (maybe it’s because of the HDF core). Any suggestions of a cork flooring that has the texture, feel, and softness of the underlayment but with the integrity to act as actual flooring?

This thread is so similar to my dilemma at the moment looking for underlayment for a treadmill. The concern with some types of equipment, I believe, is that carpet may restrict the airflow around the motors of equipment close to the ground and may also shed fibers that can damage equipment. I'd be a little worried with bare feet around heavy equipment myself. TOPO shoes are a great natural alternative with minimal to zero heel-to-toe rises that might mimic the cushy feel the OP is seeking and would also offer some protection against accidental equipment impact to toes.

@SJ McCarthy thanks again. The iCork website said the flooring could be used with radiant heat, so now I’m completely confused. Carpet isn’t an option for us. We absolutely loved our infloor heat in our last house, but most of that floor we just did a finished/stained concrete application for flooring. For this house the plan was to do polished concrete everywhere, but unfortunately that didn’t work out (long story, but a problem with the concrete put a halt on that plan). So not only have we had to change our plans for the flooring for the main part of the basement, but now I’m learning I have a bunch of issues to deal with when it comes to the exercise room flooring. Ugh. First world problems!

@Aglitter keep me updated on what you decide. Also, thanks for the shoe recommendation. I’ll probably keep lifting barefoot :), but I need some new walking shoes and love the zero lift ones.

Yah...I know the cork CAN be used for HYDRONIC in-floor heat. That doesn't MEAN it allows the HEAT through. In other words, there will be NO DAMAGE to the floor NOR the hydronic system if you use the cork over top. We (cork flooring experts) will not tell you HOW MUCH HEAT you can expect to 'push through' the cork.

Cork is 3x more insulating that regular wood. So...if 1/2" of solid hardwood has an R-Value of 0.65 (per cubic inch...that's the value given just incase anyone is curious). If you multiply it by 3, you get very close to cork's R-value: 1.95 for the same 1/2" thickness.

Carpet with foam insulation R-value 1.23

These numbers don't sound very far apart but they are...trust me. Just because something is 'allowed' doesn't mean it will work they way you think it will.

Cork + Hydronic is safe. Heating a space with hydronic+cork = different topic.

@SJ McCarthy that makes sense. I never even thought about rendering the heating value of our radiant heat essentially useless by over insulating with our floor covering. Seems like this is something “someone“ (contractor, heating guy, flooring people???) should have mentioned to us. Thanks for taking the time to help me sort through this.

No problem. I know it is confusing. Remember: the DOLLAR amount is what your people are looking for. The radiant heat company = wants a BIG installation because it is BIG money.

The GC wants you to go with radiant heat because it is BIG installation and s/he gets a piece of that pie. Flooring people (the installers) often have nothing to do with what is allowed and what isn't or what is effective and what isn't. They want the 'job' because it pays $$$$$.

Everyone will have their hands out. Everyone. And iCork is no exception. I'm someone who likes to PREVENT complaints before they happen (because I'm technical support AND the complaints department). Which is to say I will PREVENT a purchase from happening (easier in Canada....customers are quite interested in hearing 'why not') BEFORE it comes back to me on a 'technical issue' (your question would be, why is my house not warm? I thought cork was supposed to be warm?) or on a 'complaint level' (your complaint would be: 'Why wasn't I told?? You KNEW I had infloor radiant heat! Why didn't you STOP ME?').

Yah. I know. I'm probably one of the best of the WORST types of sales people. I'm honest...and I will dissuade customers from purchasing if I KNOW it will come back to HAUNT ME! Sigh.

Trust me. I've had run-ins with shop owners about how honest I am. The sale I lose today is always the one they remember. They never remember the 10 MORE that walk through the door because the customer 'trusted me' (because I wouldn't let them buy)....

Anyhoooo. I digress. I'm glad I could help. I'm sorry I caught you AFTER the expensive hydronic heating system was installed. Normally I can help people save $10/sf on the system...if I hear about the project BEFORE the hydronic is agreed upon.

@countrygirl2323 I was out shopping for treadmill mats today, and sure enough like @SJ McCarthy said, the rubber smells atrocious. You might take a look at carpeting designed for outdoor, marine, convention center, or other commercial environments. You can get basically any level of plushness and any color you would desire, and it might help offer the feel you want while still allowing the hydronic heating system to be effective. I just need a small platform for a treadmill over carpet and am vacillating between a short-pile rug or something more substantial like a wood platform.