P:+1 (800) 875-5285
Mon-Fri, 7:30am-5:30pm CST
F: +1 (800) 408-1100

CeraZorb® Insulating Synthetic Cork Underlayment (2’ x 4’) - 1 Sheet

CeraZorb® Insulating Synthetic Cork Underlayment (2’ x 4’) - 1 Sheet

CeraZorb Underlayment Description

CeraZorb is a synthetic cork underlayment that is installed on top of a subfloor and below a heating element. It is recommended when installing an electric floor heating system over a concrete slab to prevent heat loss. By creating a thermal break, the heat is prevented from sinking into the concrete, and more heat radiates into the floor covering and room. In addition to preventing unnecessary heat loss, CeraZorb provides sound dampening benefits and double the crack isolation benefits when compared to cork.

CeraZorb is lightweight—up to 25 times lighter than traditional 1/4" backer board. It is available in 2’ x 4’ and 4’ x 4’ sheets, and in packs of up to 100. CeraZorb is a 5 mm. (roughly 3/16 in.) thick, synthetic cork underlayment system that is specifically designed for setting tile and stone and is an excellent insulation choice under our TempZone™ electric radiant floor-heating product. It’s a very resilient underlayment with compressive strength of 34 psi at 10% deformation.

This 2’ x 4’ sheet is pre-cut and works well for either tight spaces or large areas.  Minimum order of 4 sheets required.


Insulation Specification

Acoustic testing on 6" slab, no ceiling IIC 52 wood construction. FIIC 59 - 7.5" concrete slab. ΔIIC 20 - 6" concrete slab
Compressive Strength 34 psi @ 10% Deformation
R-value 1.5

Product Dimensions

Coverage 8 sqft
Length 4′
Thickness 0.187″
Weight 0.55 lbs
Width 2′


Shipping Height 0.167 in
Shipping Length 48 in
Shipping Weight 0.7 lbs
Shipping Width 24 in

Warranty / Certifications

TCNA Robinson test Light Commercial
Warranty 5 years

Customer Reviews

CeraZorb Underlayment achieved an average rating of 5.0 stars with 15 reviews by our customers.

Ron L., Albert Lea, MN on 08/13/2017

Great product

CNR G., PASSAIC, NJ on 05/14/2017

Great product, fast shipping

Great product

Tim O., BELLEVILLE, IL on 02/03/2017

Great product, would highly recommend if you are putting a heated floor over a concrete basement floor. They are pricey though if you need a lot.

Great Protection and Resistance

Mike T., Fishers, IN on 01/08/2017

This product was easy to install and added great protection and resistance between the slab an the heated floor.

I will be using this system on all future jobs

Bruce A., WOODCLIFF LAKE, NJ on 11/03/2016

Great product with exceptional customer service. I will be using this system on all future jobs.

Very impressed

Graeme H., EDMONTON, AB on 09/07/2016

Very impressed with the insulation value of these tiles especially for being only 5 mm thick.

Miriam N., Brooklyn, NY on 06/10/2016

Robert G., NEW YORK, NY on 06/05/2016


Robert S., AVERILL PARK, NY on 04/18/2016

This product is great. My radiant flooring grid would not have worked AT ALL if I hadn't used your CeraZorb mats. I tested the insulation properties by standing barefoot on my cold concrete floor. Then I stood on your product & the difference was AMAZING. I felt absolutely NONE of the coldness of the concrete. Thank you for coming up with this underlayment!

Quick warmth!

Kathie S., Punta Gorda, FL on 04/16/2016

I'm sure the cork is in large part responsible for my tile floor warming up so quickly!

View all customer reviews