What is Fireplace Mortar? [Explained]

  • Fireplace mortar is a silicate based refractory cement caulk used for tuck-pointing damaged fireplace mortar joints and repairing cracked or chipped firebricks in fireplaces and wood-burning stoves.
  • A good mortar, like this (Source), Quikrete brand fire mortar, it is able to withstand temperatures of up to 2000˚F (1093˚C) and meets ASTM E 136.


Will regular mortar work for a fireplace?

No, regular mortar will not work for fireplace repair. Fireplace mortar is specially formulated to withstand high temperatures and the constant exposure to heat and flames that a fireplace endures.

How do you make a fireplace mortar?

Fireplace mortar is made with a mix of silica, alumina, and calcium oxide. These ingredients are combined with water to create a thick paste that can be spread over the surface of the fireplace.

A long story about using fireplace mortar to repair my fireplace


I was having some trouble with my fireplace. The mortar joints were starting to come apart, and I had a few cracks in the firebricks. I wasn’t sure what to do about it, so I did some research online. I found that I could use fireplace mortar to repair the mortar joints and the firebricks.

I went to my local hardware store and picked up a bag of Quikrete brand fireplace mortar. The instructions said that I should mix the mortar with water until it forms a thick paste. I followed the instructions and spread the mortar over the surface of the fireplace.

The mortar was really thick and sticky, and it was hard to spread it evenly. I managed to get it all over the fireplace, but it was a bit messy. The mortar started to dry pretty quickly, so I had to hurry up and smooth it out.

Once the mortar was dry, I waited for a few days to let it cure properly. After a few days, I lit a fire in the fireplace. The firebricks stayed nice and cool, and the mortar joints held together perfectly. Thanks to the fireplace mortar, my fireplace is now back in working order!

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Hi, my name’s Eugene Duke and I love sitting by my fireplace reading a book and sipping on an adult beverage. Do you have a fireplace in your house? I’ll help you figure out the best type and style of fireplace for your home.


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