Can You Use Regular Mortar For Fire Pits?
We visited a friend recently who had built a fire pit in his backyard. It was great to sit and chat by the fire as the nights were cold. After a few weeks, he told us that he had started to notice his fire pit looked a little worse for the wear, and he didn’t know why. I wanted to know what kind of mortar he used. He looked perplexed when he asked if it was possible to use regular mortar for a fire pit.
You can use regular mortar for a fire pit, but experts don’t recommend it. Regular mortar is made from clay, sand, lime, and cement, which are naturally fire-resistant. While it can withstand the heat, the heat will damage the regular mortar over time. Using or making firebrick mortar works best.
After I explained more about regular mortar and if you can use regular mortar for firepits, my friend knew how to go about fixing his fire pit. I knew he might not be the only one who has wondered about this subject, and I thought I would share the information that helped me build my fire pit and helped my friend fix his fire pit.
We have an Fire pit mortar infographic that maybe useful that highlights some of the options for mortar and firepit’s you can share or click the image below.
Can You Use Regular Mortar For Fire Pit?
Technically you can use regular mortar for your fire pit, but it won’t last long. Regular mortar is mostly made up of clay, sand, lime, and cement. These elements are naturally good at resisting fire, but that doesn’t mean that they don’t get damaged.
When you use regular mortar for a fire pit, you will find that the fire pit will withstand the heat for a while, but it will start to crack and crumble after a few uses. If you want to build a fire pit, the best cement to use is a high heat refractory concrete mix called firebrick mortar, or you can use the cheaper version called fire-resistant concrete.
If you don’t want to buy this cement premixed, you can easily make some yourself that will ensure your fire pit will last as long as possible without getting fire damage.
We also have an article on building a fire pit without mortar if you are looking in that direction.
Types of Mortar for Fire Pits
There are many kinds of materials that are used in fire pits. These materials include concrete, firebricks, and high-temperature mortar. You can also use natural stone or other materials for a unique look. Here are a few common types of mortar:
High-temperature mortar
If you’re interested in using a high-temperature mortar for fire pits, you’ve come to the right place. This product is specially formulated for use around fire pits, and it adheres well to metal surfaces. It is not suitable for rendering or gap-filling applications.
Firebricks
When building a fire pit, it’s important to choose the appropriate bricks. Bricks for fire pits must be made of high-quality refractory cement. Refractory cement usually comes in a bucket and has the consistency of peanut butter.
After buying firebricks, you’ll need to create an interior overhang of 25mm. A thin layer of mortar on the bricks will serve as a foundation and will be filled with refractory cement. You’ll need about 80 bricks to build a medium sized fire pit.
Concrete
When it comes to installing concrete fire pits, there are some important things to keep in mind. The first step in the process is screeding. This process will make the wall of the fire pit smooth. Next, cut a length of PVC to fit inside the pit, about one foot. Oil the PVC so it will not stick to the concrete. Now, you can slide the PVC into the inner and outer holes of the pit.
Sakrete(r) Adhesive Mortar
When setting masonry units in a fire pit, high-heat mortar is recommended. This mortar is suitable for use with fire brick or clay masonry and is highly workable.
Use this mortar for parging the smoke chimney chamber and setting clay flue liners. It is rated for use up to 2550 degrees Fahrenheit. Its excellent strength properties and ability to resist heat make it ideal for setting these types of materials.
Retaining wall blocks
Building a fire pit can be a relatively simple task if you use retaining wall blocks. They do not require mortar, fire brick, or inserts, and they are available in a variety of colors and styles.
Some retaining wall blocks are designed with a 1″ lip on the interior of the bottom portion to help secure the pit to the ground. Before you get started, you should check your local ordinances to make sure the fire pit you build is permitted.
Steel fire rings
There are many benefits of using a steel fire ring with your fire pit. It is inexpensive, easy to use, and multipurpose, making it an excellent choice for lining a fire pit. In addition to containing fire, a steel fire ring can also be used as a raised flower bed.
Difference Between Firebrick Mortar And Regular Concrete
When you want to build a fire pit, the first thing that comes to mind is using concrete. But not all concrete is made equal, or is it? According to leading experts, regular concrete can resist heat up to a point, but when faced with prolonged direct heat, the concrete will dry out and start to crumble.
Firebrick mortar is made from high heat refractory concrete that is mixed with other fire-resisting elements to create the perfect concrete mix that you can use to make a fire pit, pizza oven, or outdoor BBQ. The next section will look at how you can make your own firebrick mortar mix at home to build a long-lasting fire pit.
How To Make Firebrick Concrete
When you want to build a fire pit, it’s important to use the right mortar. If you use the wrong kind, your fire pit will eventually lose structural integrity, crack, break into pieces and crumble.
Remember to wear protective gear when mixing the powders as they are dusty and can lead to lung damage if you inhale them. Use a dust mask with a respirator, gloves, and safety goggles to protect yourself.
The Supplies
Here are the supplies you will need
- Mixing container
- Garden hoe
- Water
- Portland cement or calcium aluminate cement
- Lime
- Fireclay
- Sand
The amounts of each product you need will depend on the size of the fire pit you want to build. It is a guideline to make one batch of firebrick mortar.
The Method If You Are Using Portland Cement
Making firebrick mortar is very easy, and you are assured that your fire pit will withstand the heat of the fire and won’t get damaged over time. Follow the steps below for the best results.
Step 1
Add ten parts of sand to the container. (make sure it’s clean and dry)
Step 2
Add six parts of fire clay to the sand in the container and mix well.
Step 3
Add two parts of Portland cement to the fire clay and sand mix. Mix the concoction thoroughly.
Step 4
Now add three parts lime into the mixture and mix it thoroughly using the hoe.
Step 5
Now for the water. Add water to the mixture a little at a time while mixing it. Keep adding water and mixing it through until you get a consistency that matches peanut butter.
Step 6
Now you can apply the mortar to the brick. Ensure that the mortar between the bricks is not thicker than ¼ inch, as it will help prevent cracking when the firebrick is heated.
The Method If You Are Using Calcium Aluminate Cement
If you are not using Portland cement but calcium aluminate cement, the process is simpler as you don’t need to add lime to the mixture. Here is how:
Step 1
Add ten parts of sand to the mixing container (make sure it’s clean and dry).
Step 2
Add three parts of calcium aluminate to the sand and mix thoroughly with the hoe.
Step 3
Next, add one and a half parts of fire clay to the sand and calcium aluminate mix. Fold it in thoroughly. Add a little water in at a time and mix it until you get a consistency that matches peanut butter.
Step 4
Now you can apply the mortar to the brick. Ensure that the mortar between the bricks is not thicker than ¼ inch, as it will help prevent cracking when the firebrick is heated.
Conclusion
When you want to build a fire pit, it’s best to use firebrick mortar that you can buy premixed or make yourself. Using regular mortar is not a good idea, as your fire pit will start to crumble and break apart after a few uses.
Regular mortar might have fire-resistant properties, but it can still get damaged over time. Mixing your own firebrick mortar is an inexpensive way to build a quality heat and fireproof fire pit that can last years. Remember to wear protective clothing to protect your mouth and eyes from the dust of the products.
