Gather ‘round and learn how to build your own outdoor fireplace
A backyard fireplace is the perfect warm and toasty gathering spot, a means for roasting marshmallows, and a way to get more use from your outdoor space when the nights get nippy. If the cost of a pro installing your outdoor fireplace or a premade kit burns you up, you can save big by going the DIY route.
But know this: You should have some masonry knowledge if you want to tackle this project, as the planning and execution can be challenging without it. We get into s’more detail below.
Before you begin the build, check in with your local permit office to see if there are any codes or restrictions to abide by. Certain municipalities also require building permits for outdoor fireplaces. Either way, you don’t want to find out you needed this important documentation after you’ve already completed the project.
Prior to hitting the bricks, you’ll need a solid plan to help you figure out what materials you’ll need (and how many). Measure out the area you’d like to fill and create a rough sketch with the dimensions.
If you don’t already have a concrete slab to build on, prepare one by digging a ditch and tampering the soil down. Then, add a layer of gravel, pour the concrete, and allow it to cure.
Referring to your drawing and dimensions, begin laying the cinder blocks that shape the woodbox of your fireplace. Keep the center hollow for the firebox and create a “U” shape. Mortar the first layer of blocks to the concrete, then stack and mortar more blocks until you reach your desired height.
A lintel acts as a support beam that runs the length of your fireplace. Cut your steel angle to the right size (or purchase the exact length if it’s available). Lay the lintel across the front of the woodbox for support.
Lay as many hearth blocks as needed to cover the top of the wood box. Be sure to mortar securely around the seams.
Stack fire bricks on top of the hearth blocks to create your firebox. Mortar these together as you did for the wood box.
Cut the second steel angle so it runs the length of your fire box. Place this across the front of your fire box for added support.
Once you’ve built the firebox, add the chimney cap to the top of the fireplace.
Cut your cement board to fit around the exterior of your fireplace. Securely mortar down each piece of cement board.
After you’ve laid down and mortared your cement board, nail it into place with masonry nails and a masonry hammer.
Your last step is laying down your veneers of choice. Add a layer of mortar to the cement board and set your veneers firmly in place.
Before you set your fireplace on its maiden voyage, allow all your materials to dry fully. Then, examine the firebox and seal any cracks if needed.
If reading through those steps left you feeling overwhelmed, you’re not alone. This project is best suited for those with prior masonry knowledge. From the design to building the actual structure, it’s not something the average DIY-er can typically pull off.
You could also go another route; a firepit costs less than an outdoor fireplace, plus it is much more DIY-friendly (and will toast marshmallows all the same). These can be gas or wood, though gas varieties require the knowledge of a professional. Either way, there are tons of unique fire pit ideas, so you can still create a gorgeous design that will light up your outdoor space.
Professionally installing an outdoor fireplace costs quite a bit more than the DIY, but it’s worth the investment if you’re dead-set on an outdoor fireplace. This is a build you shouldn’t attempt unless you’re totally confident that you can safely accomplish it. When in doubt, reach out to a local mason.
