HEAT STOP is a premixed and ready to use refractory mortar. It was developed for installation of firebrick in masonry fireplace installations. It also has many other uses such as in chimneys, boilers, furnaces, kilns and etc.

  • This refractory mortar is gray in color and is shipped in 15 lb. and 50 lb. plastic pails.
  • For estimating purposes 50 lbs. will lay up approximately 100 firebricks (2 ½ inches thick) if joint thickness is 1/16 inch to 1/8 inch as recommended.
  • Mix thoroughly. No other additives required.
  • If frozen, unfreeze and mix thoroughly.
  • Meets and exceeds ASTM C-199 medium duty.
  • Meets all local and national building codes.
  • Good for applications well over 2000 0F.
  • HEAT STOP premixed is an air setting product, however may be water soluble in service. Do not use on exterior applications or where excessive moisture may be present. Use HEAT STOP II or HEAT STOP – 50 non-water soluble products for moisture present applications.

TIP when using Heat Stop Premixed. For best results:

Mix all of the contents in the container thoroughly before using.
If, after mixing, the product still appears dry, add a little clean water and remix it thoroughly.
For firebrick installation, keep the joints 1/16″ to 1/8″ thick.
This product may take longer to dry if the joints are thciker than 1/8″, and/or if conditions are extremely humid (such as after a recent rain). To enhance the drying in such conditions, open the damper, place a fan in front of it, or use other means to get some air or heat passing by the installation.

This convenient pre-mixed, ready-to-use product is available in one-gallon or 50-lb. pails. This product works well in firebrick installations such as fireplaces, boilers, furnaces and kilns. Gray color. Also available in beige color. Water soluble.