how to build an outdoor fireplace

How to Build an Outdoor Fireplace: Easy Steps to Follow

Are you planning to take your home exteriors to the next level? Then, how about building a fireplace? An outdoor fireplace can serve as the backbone of any home exterior. It provides an area where people love gathering and spending cherishable moments with families and friends. Like hot tubs, barbeques, and outdoor kitchens, fireplaces are also effective in drawing people together.

So, if you are wondering how to build an outdoor fireplace in your backyard, this easy step-by-step guide is for you. Follow these instructions and create a premium-looking ambiance outdoors by turning your backyard into a favored spot for your family and friends.

Things You Will Need to Build an Outdoor Fireplace


  • Protective gloves
  • Tape measure
  • Hammer
  • Tamper
  • Circular saw
  • Shovel
  • Bubble level
  • Wood or metal stakes
  • Shovel
  • Masonry hammer
  • Concrete trowel
  • Square
  • Hacksaw
  • Hoe
  • Mortar mixing pan


  • 33 full concrete cinder blocks (8x8x16 cubic inches)
  • Manufactured veneer stone
  • 12 half-concrete cinder blocks (8x8x8 cubic inches)
  • Nails (2 ½ inches) 
  • Six cement backer boards
  • Two metal flue caps (24×24 square inches)
  • Mortar
  • Six hearth blocks (each 42 inches by 32 inches)
  • Two steel angles (1 ½ inches by 72 inches) 
  • 6 50 Pounds bags of gravel
  • 26 80 Pounds bags of quick-set concrete
  • 2 two-by-sixes
  • Masonry nails 
  • Rebar (42 inches by 6 feet)

Steps to Build an Outdoor Fireplace

Step 1: Check Local Codes

Make sure to check any state, local, or HOA codes and restrictions for an outdoor fireplace. Generally, the process is as simple as meeting clearance requirements for property lines. As open fires could be banned in your local area, it is essential to check with your local permitting office for any restrictions related to outdoor fireplaces. Also, air quality measures may prohibit wood-burning fireplaces in your area when air quality is poor.

Step 2: Locate the Outdoor Fireplace

Determine the right spot to build the outdoor fireplace. It should be close enough to your home for easy access but adequately distanced so as not to cause safety hazards or nuisance. As per local codes, outdoor fireplaces should be at least 20 feet away from the house. After all, the patios nearby can trap smoke. Also, the area underneath the fireplace should be strong. Additionally, if there is any water collecting area around or under the fireplace, the water should be drained away, as it can lead to cracking of the concrete pad.

Step 3: Clear and Level the Area for the Pad

Before you start with the construction, you need to clear and level the ground for the pad. So, excavate a section of dimension 70 inches by 56 inches in the ground. Then, level it and tamp the solid down with the tamper. Also, spread about 2 inches of gravel and flatten it.

Step 4: Build the Fireplace Pad Form

Cut the two-by-sixes into two sections of 68 inches long and two sections of 40 sections. Use hammers and nails to make the concrete form and place it in the gravel. Use the square to make sure the concrete form is perfectly shaped. Cut the rebar to size. Now, place the wood or metal stakes around the concrete form to keep its square form, level, and in place after you pour the concrete inside.

Step 5: Pour the Fireplace Pad Concrete

Now, get the concrete ready. Mix the quick-set concrete in the mixing pan using the hoe. Pour half of it into the form. Place the rebar around the form (about 6 inches from the edges) and pour the rest of the concrete.

Step 6: Let the Concrete to Cure

Don’t remove the concrete form for one or two days. The concrete will be cured to work in a span of 4 to 5 days and fully within a month.

Step 7: Place the Fireplace’s Wooden Box

Place seven of the full-size blocks, shaping a U-shape. Like, three in the back and two on each side. Lay two half-size blocks at the end of the U-shape. Then, place them on the concrete pad and mortar them. This is the bottom course of the blocks in a three-block level box. For the second course, alternate the blocks. The seams from the first course should meet the middle of the upper one. For the third one, just duplicate the first course at the bottom.

Step 8: Create the Lintel

Use a hacksaw to cut the steel angle to 68 inches. After that, place it across the front of the wooden box for support, just like a lintel.

Step 9: Lay the Hearth Blocks

Now, securely mortar down the two hearth blocks on the top of the wooden box. Also, mortar the seam in between the two hearth blocks.

Step 10: Build the Firebox

Now, you have to build the firebox on the top of the hearth blocks and a smaller version of the wooden box. Use two full-size blocks across the back and one and a half full-size blocks on each side. After that, build three courses following the method used to build the wooden box. Then, use the hacksaw to cut the steel angle to 48 inches. Place it across the firebox’s front part for support, just as you did in Step 8.

Step 11: Add the Chimney Caps

Add the two chimney caps next to each other on the top of the firebox.

Step 12: Place the Veneer Stone

Cut and place the cement board across all areas of the fireplace that will receive the veneer stone. Mortar down the board and nail it into place using masonry nails. Then, mortar down the veneer stone on the cement board.

The Final Thoughts

Hopefully, you will be successful in building your outdoor fireplace by following this guide on how to build an outdoor fireplace. Now, just enjoy your new fireplace and relaxation centerpiece. 

Also, don’t forget to visit Home Online Solutions and explore more such decor ideas and DIYs to upgrade your home interiors and exteriors.