Cork as underlayment [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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jane m
10-06-2006, 10:58 AM
You guy have helped me with a few projects so far (THANK YOU), and now onto the basement...

I cannot afford Ditra this time, so I'm leaning towards cork to provide a little insulation b/tw the slab and the floor heat (+ceramic) and, so they claim, stress crack prevention.

One site recommends 1/8" (3mm) for the purpose of crack prev. I know thicker would be more insulating, but this would get the job done, and I prefer to go with the one best suited to provide a little protection.

Others say 1/4" (6mm) or 4mm. Some say sheets (2' x 3'), others say rolls.
Also, adhesives run the gamut...

Comments please??

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10-06-2006, 05:13 PM
Look at EasyMat from Custom Building Products. If you basement floor ever gets wet, I think it might be a better choice, but it would be best to call them and ask.

10-06-2006, 08:12 PM
Jim is right, check into easymat. It's made for tile and I believe it's about R-3 (may not seem like much, but will make a big difference with in floor heat) I can't imagine that it would cost more than cork, but then, I can't believe Ditra would cost more than cork either. How much did your Ditra cost you (It cost me about $0.85 if I get at a distributor and $1.10 if I get a small amount from a tile shop) and where are you getting cork for less?

10-06-2006, 08:21 PM
If you put the cork down with cork glue in a damp basement the glue will fail.I also don't think the cork will provide any insulation against cold, but it may prevent cracks.If you're talking about heat mat go with what the manuf. recommends.But cork tends to give tile a clippety clop sound when you walk on it. :goodluck:

jane m
10-11-2006, 05:53 PM
Thanks for all the input guys. Many of the floor heating people do recommend cork, but I can't get the cork manu. to sign off b/c they think it might dry it out. Also, failing cork glue in wet conditions makes sense....

I go to the customs site and can't really find good info about easymat. Who do I contact for more info. and to buy? Does anyone know the price? Thanks....

10-11-2006, 06:06 PM
Unless your a contractor most Dist. will not sell the general public.I have stated this in the past but I feel contrators ON THIS SITE need to keep THEIR prices away from the general public. Some mark up product cost...

jane m
10-12-2006, 09:57 AM
So ya'll are telling me to use something that I can't have? :scratch:

Pacta Floor Guy
10-12-2006, 10:40 AM
I believe you can purcchase the same product under a different product name called CeraZorb. Google CeraZorb and you should find it

jane m
10-12-2006, 11:41 AM
OK, found it: Cerazorb, 400 sf $400, 3/16", R value .8

This looks like a winner. They'll ship it to me in two days. It will go down over SLC, under heat mat, and I can thinset it down. WarmlyYours recommends Easymat (same product), so I guess R value .8 will suffice for insulation?

Anyone have anything else to add before I buy?

:suspect: or :tup1:

John Bridge
10-12-2006, 04:45 PM
I have something to add. Why can't you use Ditra? It's the best answer for the situation you have. :)

I recommend EasyMat for under the heat installation. Is that what you have in mind? If so, use modified thin set to put down the mat on the concrete, not the glue type.

jane m
10-13-2006, 08:27 AM
Well, as I stated above, I thought I couldn't afford Ditra....but....350 sf will cost $490. CeraZorb will cost $450, and I haven't found a price on WEDI, but I think it is higher. seems as if Ditra and CeraZorb are definitely preferred over cork, so I'm sure willing to spend the little bit extra (cork only costs $200-300).

Does everyone agree with JB that Ditra is the best? Warmly Yours only recommends cork or WEDI?????

Your advice is appreciated, I need to buy this stuff ASAP with winter coming and I've been putting this off for months trying to figure everything out. :shrug:

JB has recommended easymat before, can I get confirmation from anyone that CeraZorb is the same quality and thus also recommended? Their techs say it is...

This time JB said Ditra is best, anyone want to vote on that? I still haven't priced WEDI, but might consider if cost allowed. The prob w/ Ditra is I get no insulation....

Also JB said Easymat has an R value of 1.7, but I believe that is per inch or something, which means that whether I use easymat or CeraZorb, for the size I would get, the R value is .8 I think.

I'm getting really confused again... Can anyone help? :confused:

jane m
10-13-2006, 10:21 AM

10-13-2006, 10:33 AM
Hi Jane,

See my disclaimer, but I used Ditra over Warmly Yours mat buried in SLC -- works fantastically. I wouldn't worry about the insulation factor. You'll get a good thermal mass from the thinset and tile over the Ditra. My floor warms up fairly quickly and is nice and toasty. Worth spending the money on the programmable thermostat, too, if you only use the space on occasion.

Can't comment on the Cerazorbiwhatsit... ain't never heard of it. Again, see disclaimer :)

10-13-2006, 01:20 PM
I would think that Customs Easy Mat is much higher then .8 R Value.
Nobleseal is .8 !!... we would tell you .8 is basicly nothing ..

jane m
10-13-2006, 03:15 PM

The R value is .8 on the 3mm, 1.5 on the 5mm, and 3.75 on the 12mm, but wouldn't I use the 3mm or 5mm? CeraZorb (that is available to me online) is 3mm.

Cork is 2.6 for 1/4".

So, do you see my dilemma? I want to believe that Marcus is right, but the floor heating folks say otherwise???

So, unless WEDI is affordable, it's going to have to be cork or CeraZorb. Anyone????

10-13-2006, 06:53 PM
like I said .8 is next to nothing..we have that with Nobleseal and claim next to nothing for R Value, but can offer crack protection ,waterproofing. Also HD with regaurd to load rating for the tile..(won't compress and break tiles)