How to Install Cerazorb to Cement Slab. Can Vinyl (LVT/VCT) be installed directly on Cerazorb?


An overview of how Cerazorb is attached to a cement slab prior to tile setting.  Instruction on how to install Cerazorb under LVT/VCT and vinyl.

Here's an email from Impacta concerning roller weight:

Jamie Vallee

9:39 AM (25 minutes ago)

to me

A 100lb roller is fine.  The min is 35lbs.  Hope this helps. 


Jamie Vallee

Product Manager

Sound Seal / Impacta Flooring Division

50 H.P. Almgren Dr

Agawam, MA 01001

Phone: 413-789-1770 ext 135

Fax: 413-789-2248 



Surface Preparation

Surface must be structurally sound, clean, dry and free from dirt, oil sealers or any contaminants that would prevent a good bond. CeraZorb must acclimatize in their sealed packaging for 48 hours at a temperature of 65 degrees.

Inspect concrete sub floor for any open cracks and fill with a high grade patch. Remove any excess concrete lumps or residue that may interfere with the installation of CeraZorb. The concrete slab should be fully cured, dry, smooth, flat, and accept water penetration. Concrete must be free of efflorescence and not subject to hydrostatic pressure. A good quality concrete waterproof sealer may be required if moisture in the slab is above 10%.

1.  CeraZorb can be bonded to the sub floor with Impacta T-440 bond coat adhesive. Use a 1/16” x 1/16” x 1/16” square-notched trowel.  Apply only enough adhesive as can be covered by a 4’ x 4’ sheet. Clean up any extra before the adhesive skins over. Impacta T-440 and the sub floor must be at 65ºF (18ºC).   Armstrong S-235 Multi-Purpose Adhesive is OK according to Soundseal. Roberts 6700 Indoor or a high quality outdoor carpet adhesive are also OK. 

 2.  CeraZorb can be bonded to the sub floor with any high quality latex/polymer modified thin-set (recommended, but not sold through WarmlyYours). Use a 1/8” x 1/8” x 1/16” V-Notched trowel.  Apply
only enough adhesive as can be covered by a 2’ x 4’ sheet. Clean up any extra adhesive before the adhesive skins over.  The thinset and the sub floor must be at 65ºF (18ºC).

Set the CeraZorb into the adhesive while it is still wet.

Do not allow adhesive to skin over. Lift a corner periodically to see if the adhesive is transferring 100%. If adhesive is not transferring, apply additional adhesive. Flat trowel the CeraZorb to smooth out air pockets. Continue to install CeraZorb sheets making sure to install with edges butted tight to each other, do not overlap seams. After first row is completed, roll the mat with a 50 lb roller. Install second row with staggered seams to the first row and repeat steps above. It is recommended to wait 8-12 hours before installing tile on top of CeraZorb.

Can pressure sensitive adhesives be used to stick down the CeraZorb?  No.  This installation method is not mentioned in the Installation Manual and should not be recommended.

Can LVT and VCT go directly onto the surface of CeraZorb? --NO.  Put a skim coat of SLC, or even plywood over it first.  Then, LVT/VCT can be installed.

Content taken from Cerazorb installation instructions at this web address:

Added by AISA 4/6:

Many self leveling cement manufacturers recommended priming Cerazorb when using SLC over it. When using primer, follow the mixing instructions specified in the product instructions or on the label. 

Written by Christopher Sphar
Posted on

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