Build Your Own Backyard Fire Pit

 by Thisoldhouse.com
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Outdoor fires are so hot right now. Seriously. Mankind has called the hearth home for the centuries, it's true, but these days people are going ultra-retro and getting their heat from stone-walled pits set into the earth. And, why not? On cool summer nights, you can melt marshmallows and nibble s'mores while you lounge in an Adirondack chair, feet propped up on the rock ledge. So if you really want to light up right, do it in style. Take a few days to build your very own ring of fire.

*See final slide for a SHOPPING LIST for this project

 
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Step 1: Learn the anatomy

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A built-in fire pit is a glorified campfire, with sturdy walls of stone that help contain the flames and heat. That's especially important in the parts of the country where there's a risk of brush fires. So the first task in building any fire pit is checking local codes on open flames. The pit must be located far from overhanging trees, the house, and any other flammable structure.

MORE: Landscaping That Prevents Wildfires

To make building stone walls easier, you can use blocks made from cast concrete and molded to look like real stone (available at any home center). They're flat on the top and bottom so they stack neatly, and some interlock for added strength. Glue them together with masonry adhesive. Choose a block with angled sides, meant to form curves when butted against each other. The optimal size for a fire pit is between 36 and 44 inches inside diameter. That will create enough room for a healthy fire but still keep gatherers close enough to chat.

As an added precaution, the fire pit should be lined with a thick steel ring like the ones used for park campfires. These protect the concrete in the blocks from the heat, which can cause them to dry out and break down prematurely.

A fire pit should sit low to the ground, with walls rising no more than a foot off the ground. But for stability, the base of the wall must be buried below ground in a hole lined with gravel, providing drainage and protecting against frost heaves in winter. the gravel also creates a level base for the stones to rest on. Most concrete blocks are about 4 inches high, so if the first course and a half sit underground, and there are two and a half courses above ground with a cap on top, you'll end up with a foot-high wall—just right for resting your feet on while sitting in an outdoor chair.

MORE: Build an Adirondack Chair

MORE: Want More Wall and Less Fire? Try Building This Fire Pit's Cousin, The Sitting Wall
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jblanton1 says: Oct 6, 2011. 3:54 PM
I'm in Texas and we currently have a burn ban due to the drought. I recently needed to burn some limbs on a piece of property that I own (but haven't built a house on it yet). As I was clearing out the brush that had grown up, I noticed where someone had dumped a concrete culvert that had about 6" x 12" half moon chip removed in one end, so I stood the culvert on it's end and used it for a burn "barrel". The hot air goes out the top and sucks in air through the half moon opening in the bottom. Once it starts up, it's like a little jet engine running. I ran it for about an hour and the concrete stayed warm for a LONG time after that. End result is that concrete seemed to make a pretty good fire barrier without fire bricks...
sandraellis says: Oct 5, 2011. 3:33 PM
I like the diagram you have showed below the finished product. Its reassuring to see how stable the fire pit really is. I too appreciate a good fire pit!
rwolkens says: Jul 4, 2011. 10:25 AM
This has given me inspiration. I have an above ground fire pit that my Mom gave me, but it is missing one of the four legs, and the screws that hold the legs to the base ring have rusted and broken off. If I make a base of decorative stone topped off with pavers, and fill the bottom with draining stone that I have laying around, then drop the pan into the top of it with the lip overlapping the pavers, that should work really good and look nice.
dbarajas2231 says: Apr 27, 2011. 9:14 AM
I understand the rational for having a fire ring, to "protect the concrete in the blocks from the heat, which can cause them to dry out and break down prematurely..." but it it absolutely necessary? The link provided for the fire rings price them at $75 to $215.28 and that seems a bit much. Is there some type of stone that I could substitute for the concrete bricks that would hold up to heat better and alleviate the need for the metal fire ring?

Thanks
starshipminivan in reply to dbarajas2231Jun 19, 2011. 7:48 PM
You can use fire brick--the kind used to line fireplaces. Home improvement stores carry them. They are NOT the same as the brick used in construction and they certainly should NOT be concrete bricks. Use these to line the inside of the pit.

We found them to be far less expensive than a custom ring and, when we did the math, were still less expensive than the least expensive rings we could find. We are building a fire pit this year and that is what we are using to line it. The exterior will have the concrete blocks but the inside ring will be all fire brick.
ddpedersen says: May 13, 2010. 7:37 AM
Not sure that putting gravel in the bottom is a good idea.  When the fire dies down and the hot coals sit on the bottom, they heat up the rocks and any air pockets in the rocks can cause them to explode.

Not horribly dangerous, but i have been hit in the face with rock fragments before.  I would just leave the bottom as dirt, plus it is easier to remove the left over coals when you are done.

Whatever you do, never put a concrete slab below a fire, they have a lot of air pockets, and per my experience, will explode and send everyone running.
JRTORRES in reply to ddpedersenMay 16, 2010. 10:02 AM
Actually, it is not air pockets in rocks, it is dissolved water. When water gets heated it comes out of solution and expand to about 700 times its volume causing an explosion. This water exist in concrete as well as other rocks. Volcanic rocks do not contain the water because of their origin, lava actually is dry since it is so hot. So there is no water during solidification. Bottom line is, do not use gravel and if you use concrete block you must cover it with the metal lining. Concrete causes a nasty explosion, lots of water in it.

Another thing that is useless is the trench filled with gravel. What's the point, if you have no drainage. It is just going to fill with water from rain and eventually it will dissolve the surrounding dirt which will cause the sides of the trench to cave in. You are better off leaving holes on the bottom of the block structure so that it drains over the ground surface.
SoDDiggerCpl in reply to JRTORRESJun 19, 2011. 10:42 AM
the point of the gravel is it is an easy substance to level, it is used in construction to create level footers. being under the first course of blocks gives the whole ring stability, and allows for level construction.
co1973 in reply to JRTORRESMay 20, 2011. 1:48 PM
The ring of gravel has nothing to do with drainage, per se. If you're not familiar with the construction of stacked concrete retaining walls, the purpose of the gravel is to provide a compactible surface that can be easily leveled prior to setting the stones. Drainage isn't a concern for the firepit because it's no different than the undisturbed ground. it sits on.

Cerasus in reply to ddpedersenMay 13, 2010. 11:49 PM
A dirt bottom is a really, really, really (and I cannot stress this enough) really  bad idea and should never ever be done for reason. Root fires are a reality and is a horrible MoFo to deal with.

Sand is the superior alternative.
GDParduhn3 in reply to CerasusMay 26, 2010. 3:37 PM
I ditto the sand bottom,    a really thick layer  , ,  you could go as far to use silica sand  , the high heat resistance stuff they use in the bottom of fireplaces.

it will drain easily too.


easy to sift out debris later. 
 

plznothanks says: May 15, 2011. 8:30 PM
Bear Grylls is the champ at this http://howtohacklife101.blogspot.com/2011/05/how-to-build-fire.html
Thefsxmad says: Nov 20, 2010. 11:04 AM
Loving the Adirondack chair
Did you build it yourself?
hg341 says: Oct 1, 2010. 1:32 PM
you need more pics
Kiteman says: May 14, 2010. 8:49 AM
Riddled with external links.

Looks spammy to me.
SaveOurSkills in reply to KitemanSep 16, 2010. 2:05 PM
hey the information is very good though... i don't mind him referencing external articles that are relevant. Also I am not opposed to people providing site with excellent content in order to promote their web ventures as long as they stay on topic. True spam just links randomly, the external links were all relevant.
nbue says: Jun 5, 2010. 7:53 PM
How would one go about safely building a fire pit on top of a cement deck? It's the only spot for one in our yard and is also the roof over our underground garage. Ideas anyone?
superant10000 in reply to nbueJul 18, 2010. 5:43 PM
My friend Erin has something very similar to what you're asking. http://www.bapatoms.net/photos/pit1.jpg The above is similar to what she has; though hers is bigger than that one. It works perfectly fine, although there are issues with pieces of flaming kindling/twigs being blown in your face when the winds pick up. If you're fully sheltered then it doesn't matter so much and I would recommend you buying something similar. If you're intent on building one DIY, then you could always just build the pit upwards using insulation and keeping a good 12" distance from the burning area base, to your garage roof. I would also recommend checking the supporting weight of the whole structure, because if the roof only supports 600KG and you build a 90KG fire pit on top and have 10 people all sitting around it, you could find yourself all being horiffically maimed then burnt alive. Wow. Was that a bit over the top? :/
adlabens says: Jun 17, 2010. 5:17 AM
I built my firepit in much the same design, but with less. I had a level place in the yard, so I simply set the bricks into a circle (took 12 bricks to make a circle. I got 4 layers of the bricks, less a few gaps in the very bottom for air flow. I broke the tabs off the backs of the bricks, broke a couple of bricks in half (2 for each of the bottom 2 rows), and laid them out. No mortar, no gravel, no metal liner - simply laid out the bricks. Then, I tossed in the sticks & branch pieces that had fallen into the yard from our 4 pecan trees over the past year, & lit it up. Took about 75 minutes from start to finish to do the whole thing, and another 15 minutes to clean up the leftover brick pieces. Two tools - hammer & chisel, and the only material was the bricks, quick & easy & effective.
rwinscot says: Jun 4, 2010. 2:13 AM
I wouldn't recommend using any kind of adhesive / glue when assembling a fire pit - you run the risk of releasing un-healthy fumes with the heat of the fire. A fire-friendly mortar would be a much better choice. Also, you don't want to make the body of the pit air-tight. Leaving cracks / spaces in the blocks here and there will improve ventilation.
codyhanson says: May 12, 2010. 7:44 PM
 On this picture it says "glue wall blocks together with"....with what?
GDParduhn3 in reply to codyhansonMay 26, 2010. 3:29 PM
must be air...    ! 


i like the mud idea better,  or clay even. ..
ahutton1972 says: May 13, 2010. 8:39 AM
Someone explain to me why he is shooting Great Stuff insulation onto his wheelbarrow?
neopirater in reply to ahutton1972May 13, 2010. 9:20 AM
Perhaps so it never goes completely flat?
naruto the ninja13 in reply to neopiraterMay 26, 2010. 7:30 AM
ya, we use Great Stuff foaming insulation in our 2 front riding lawn mower tires because its soft enough to move but its a solid so it wont leak out holes in the tire
Covert Koala says: May 20, 2010. 7:39 AM
 I spent a lot of time on a friend's farm growing up and they had two campfire set-ups that worked for years with no problem. The classic ring of stones with dirt in the middle, and an old metal barrel with minor holes on the sides (rust, etc). If you're looking for something fancier I recommend a movable metal fire pit, stands on legs off the ground, walmart has them for $50. A sure campfire exploder is bamboo. My friends and I learned the hard way when we put that stuff in the fire, bamboo is just wooden chambers filled with water.
Vrtigo1 says: May 19, 2010. 12:34 PM
 This isn't a very good guide.  When building a firepit, you need to use firebrick and fire safe mortar.  If you use regular stone, it'll eventually discolor and crack, and can potentially explode if the water inside it boils.
Cerasus says: May 13, 2010. 11:42 PM
What's the motivation of using glue instead of mortar? Seems like mortar is the more timetested choice.
punkhead58 in reply to CerasusMay 19, 2010. 8:35 AM
I didn't use either. I took the cheaper and more primitive route with this project....mud.


pedaws says: May 13, 2010. 11:02 AM
Using a caulking gun, squeeze a zigzag bead of masonry adhesive across two adjacent blocks
rocco says: May 13, 2010. 4:06 AM
This looks cool and all... but, what's the estimate on the cost of materials? (All the hardware and big box stores sell above-ground fire-pits for around $100 these days.)
xtremeleafan says: May 12, 2010. 3:48 PM
 Very nice. But the best fire pit is made from the insides of a washing machine. Remove the tub,which has small holes all round. It's safe and cheap
tytyjul97 says: May 11, 2010. 8:36 PM
my dad and uncles made a fire pit out of my mom garden bricks.
nora in reply to tytyjul97May 12, 2010. 12:13 PM
 I have one made from the garden bricks... not tempered for fire. They're almost ALL split, discolored, or completely broken. :(

Of course, mine doesn't have a metal liner in it, either.
Tectron says: May 12, 2010. 12:03 PM
Very nice, it seems like overkill to me though, but live out in outer edge of civilization.
trailleadr says: May 10, 2010. 7:43 PM
Nice 'ible.

Is that last image suggesting filling a wheel barrow tire with expanding foam?
oakback in reply to trailleadrMay 11, 2010. 10:57 AM
 That's brilliant!  Where's the instructable for that?  
trailleadr in reply to oakbackMay 11, 2010. 8:57 PM
If I had a wheel barrow, I would make the instructable.  Looks pretty straight forward.  Fill tire with expanding foam until it blows up in both you and your spouse's face.  (kidding)

I wonder how well it would work though.  The foam has the ability to get a flat spot under a heavy load, so eventually your tire would be kinda lumpy and bumpy.
Would it really be worth it in the end?
the_Magnificent_Macak says: May 11, 2010. 2:40 PM
Hey that's cheating, DIY via thisoldhouse website?
Weissensteinburg in reply to the_Magnificent_MacakMay 11, 2010. 3:04 PM
 That's what I thought at first, but look at the member's name.
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