Earthcore adhesive

The Earthcore Adhesive, is a thin-set masonry adhesive, which can be used in either interior or exterior installation. An approved adhesive for Isokern fireplace and chimney systems, the mortar is available in 50 pound pails. Properly mortared fireboxes and smoke dome assemblies require approximately five gallons (dry measure) of Earthcore Adhesive.


MEETS ANSI A118.1, ANSI A108.5 AND C.T.I. 64-1.

When blended with additional adhesives conforms to ANSI A118.4.


50 lbs of earthcore® adhesive would be sufficient per ISOKERN® ­firebox unit

10 lbs adhesive should be mixed into 1 quart of water

Allow to stand for 20 minutes, then stir again prior to use

A minimum cure is obtained in 12-24 hours, depending on ambient temperatures

For curing allow 30 days before burning wood or allow 48 hours for all gas heat appliances

DO NOT ALLOW TO FREEZE within fi­rst 72 hours

Apply earthcore® adhesive in temperature range of 40º F to 90º F (4º C to 32º C)


May cause eye, skin or lung injury. Contains free silica. Prolonged exposure to dust may cause serious lung injury. DO NOT INGEST, DO NOT INHALE DIRECTLY. Use NIOSH approved mask for silica dust. If any cement gets in eye, immediately and repeatedly rinse with water and consult a physician promptly. Avoid contact with skin and wash exposed areas with water.


We have owned an Isokern Fireplace in our home for over 9 years now. We like the Isokern pre-engineered firebox produces a consistent fire draw. In the past we had experienced some poor draws in our existing fireplaces and wanted a better fire experience. We also liked that the interior firebrick could be customized to give you various looks for the fireplace. We would definitely consider another Isokern Fireplace for our outside porch.

Barbara and Bob Dougherty

We have been working with Earthcore for many years. On the product end, the Isokern Masonry products they manufacture are second to none. The precision in which they build their components is unlike anything we have ever tried.

On the business end, we love the staff at Earthcore! From the employees I met at their factory, to the owner of the company I had the pleasure of meeting at a trade show in Nashville, TN……this company is a great organization that I look forward to growing with for many years to come.

Hill Dickerson
Dickerson Hearth Products

I’ve been woking with Earthcore for years. Claudia has been very helpful making things go smoothly out in the field and in helping with choosing the right fireplace to achieve the best looks. I have had great feedback from past customers on the product and plan on continuing to use these fireplace units.

Bruce Winfrey
Winfrey Design Build

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