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!

Eugene Duke Pic

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.


19+ Fireplace Mantel Decor Ideas For Every Season

Some of our favorite decor tips for fireplace mantels...

The Best Outdoor Electric Fireplaces [Gorgeous]

Outdoor electric fireplaces come in a variety of...

Why Does My Fireplace Have Two Switches? [Explained]

The first switch generally turns on the electrical...

Can You Move a Gas or Wood Fireplace? Yes, but…

Wood fireplaces are more difficult to move than...

Can You Paint A Marble Fireplace? Yes, but…

Yes, you can paint a marble fireplace- here are...