High-Heat Mortar

Where to Buy

Heat-Resistant Refractory Mortar for Fireplaces & Chimneys

When you’re building fireplaces, fire pits, ovens, or any other high-temperature project that calls for refractory mortar, Sakrete High-Heat Mortar is your mix.

Formulated to withstand temperatures up to 2550°F, our high-strength, highly workable refractory mix is perfect for setting fire brick, clay masonry or as a parge coat.

Sakrete High-Heat Mortar Mix shines in extreme environments where ordinary mortar fails. Its specialized formulation makes it ideal for thermal cycling, repeated firing and long-term exposure to heat. Use it for both structural and surface applications in residential or commercial builds. 

To finish surrounding surfaces, consider pairing with Sakrete Surface Bonding Cement or a Stucco Finish Coat.

Product Details

  • Use for laying masonry or fire brick, or as a parge coat
  • Performance for temperatures up to 2550°F
  • Applications from 1/8" - 3/8"
  • 1-hour working time
  • Rated for high-temperature applications in 7-10 days
  • Available in 50 lb bags
  • Yields 40-50 standard fire brick with 1/4" joints

Application Depth

1/8" - 3/8"