Thoughts on brick/rock type for outdoor fire pit??

[zan78]

We're making a fire pit. There seems to be a lot of redundant and somewhat unclear advice on the web for making one.

We dug about a foot into the ground, and it has about 4 ft diameter. Our ground is very sandy and drains well so we're planning to leave the base as just that.

What I can't find on the web is the WHYS of using brick or rock, and when a liner is or isn't needed. And whether to mortar or just stack. I wanted this to be simple - like a campfire. But I know it's wise to build something that lasts and works well too.

Do I just stack wedge shaped bricks I can get at a home depot garden section around it and call it good or do I need to get special bricks, liners etc. I don't think we'll be using it to death - just occasional fun use and maybe even get a grate and do some bbq if we desire once in awhile.

Thank you so much for your time and thoughts.

 

[zzr7ky]

Hi -

I just used a wheelbarrow full of nice roundish granite and basalt rock that I got from your area. Just a loose ring 2 rocks wide, with a single row laying on top.

It's a good way to use up marginal wood that's not worthy of stacking.

ATB,
Mike

 

[homebrewz]

Check out this thread for some ideas:
https://www.hearth.com/econtent/index.php/forums/viewthread/74052/

Use igneous or metamorphic rocks and stay away from things like shale and sandstone which can have pockets of air inside of them causing the rock to explode when heated.
As mentioned above, basalt, granite, and gneiss work well.

 

[Delta-T]

let me be the first, and possible the last to recommend precious and semi-precious stones. You will have the firepit to end all firepits. think of how sweet it would be to have the flicker of flames bouncing off rubies and emeralds, maybe a sapphire here and there...stay away from opal, its a water stone and will crumble.

 

[zan78]

How worried do I need to be about rocks exploding? I was planning on building it out of stacked rocks and then placing some thin rectangular (cement I think?) old pavers I've found around the garden.

I think my dilemma is - can I do it this way or will the pavers crumble and rocks explode...
OR should I do it this way and purchase a liner
...OR should I just get those wedge shaped bricks (and are those just as unsuited for direct fire contact).

I have no idea how much to be concerned about this or if this is just not an issue. Don't know rocks too well to trust myself to pick up the right ones in my yard. Just not keen on improper bricks or rocks exploding in our face while using it.. I will stay away from the sandstone and shale as mentioned.

 

[Delta-T]

personally, I've never seen a rock explode from heating around a fire pit, have seen rocks explode from cooling too fast around fire pit (like when you pour ice water on them). But I also havent built fire pits out of every kind of rock. Until reading this, it had never occurred to me to consider the likelihood of a rock exploding.... degrading, crumbling over time...sure. Maybe you should consult someone local-ish to you about this. Someone around you has to have a fire pit thats been in use for a few years that can give you some feedback. Man has been building fire pits for at least a few decades, probably only the last 4-5 years would most people wonder about the rock "genus". (all times are approximate, and not for use as a reference material).

 

[homebrewz]

Some sedimentary rocks will explode if super-heated, so don't have them right next to or under the fire. Having the pavers lining the outside of the ring would probably be fine. If they constantly were heated and cooled I'm guessing they would eventually break apart and crumble.

 

[PapaDave]

We just roam the back roads and pick up likely candidates to use.
Our pit was only about 3 ft. dia. when we moved in. I've since made it 6 ft. and am still collecting stones/rocks.
Only had one break in the heat, and the piece just fell into the pit instead of coming at me at warp speed. YMMV
Come to think of it, I need to shovel out some of the ash.

 

[zan78]

When talking rocks - do you all just stack them or mortar them somehow?

What I am thinking of doing at this point (a bit time crunched, want it up for some relatives coming soon) is to use what rocks I have around the place , and a liner/fire ring.. saw a descent one locally for cheap.

This would allow for less rocks until I can collect more (and maybe eventually resell the liner/fire ring if I wanted). Also cheaper than buying the wedge shaped bricks for the size I have. Any thoughts on this appreciated.

 

[Dune]

A big steel rim from a tractor trailer truck wood make a good liner. There is no hub, just a rim. You could then safely stack or mortor any rocks around the outside. Pavers are not great for lining a firepit, you want firebrick for that. Another danger with rocks around a fire pit is whethwr they are wet or not, wet rocks can explode when they get too hot, steam buildup, which is why the steel rim makes it safe.

 

[yooperdave]

When talking rocks - do you all just stack them or mortar them somehow?

What I am thinking of doing at this point (a bit time crunched, want it up for some relatives coming soon) is to use what rocks I have around the place , and a liner/fire ring.. saw a descent one locally for cheap.

This would allow for less rocks until I can collect more (and maybe eventually resell the liner/fire ring if I wanted). Also cheaper than buying the wedge shaped bricks for the size I have. Any thoughts on this appreciated.

there are some real nice fire rings available-if price isn't as issue.
my fire pit is bordered with rocks-(that tells you something). they are gathered from the shoreline and along the lake frontage. i (we) have never had a rock explode. they have cracked over time, one or two...might have even happened during the winter. i don't use any mortar, rather, i just stand them up in the desired pattern. round, or square. i only use one level of rocks. much easier to move when it is time to clean the ashes from the pit, that way. good luck, and i'm sure that whatever route you pursue, the outdoor fire pit will be a great success! (don't forget the bug spray)

 

[DexterDay]

Its as pricey as a metal fire ring from HD or Lowes. But there is a Farm & Home (Do it Best) by my house that sells a "Kit" of 2 different colors and sizes of pavers, a bag of sand and a couple bags of rock. Comes with instructions on how deep to make the pit, along with when and where to put the sand and rocks (Mexican Beach Rock) and the spacing of the pavers at the bottom for air. Its a really nice kit. I think its $115-$130. I know, a little pricey, but its a good 40" in diameter. My Firepit.. Is a Burn pile. It cuurently has a Couch, Love seat, Broken skids, junk wood, any cardboard or Copius amounts Paper (Appliances, B-days, X-mas).. Not pretty, but around here we call it a Bon-Fire. I have a dinky little Metal firepit up at the house (Bought from HD) for nights we wanna make Smores or for little gatherings.

 

[zan78]

Its as pricey as a metal fire ring from HD or Lowes. But there is a Farm & Home (Do it Best) by my house that sells a "Kit" of 2 different colors and sizes of pavers, a bag of sand and a couple bags of rock. Comes with instructions on how deep to make the pit, along with when and where to put the sand and rocks (Mexican Beach Rock) and the spacing of the pavers at the bottom for air. Its a really nice kit. I think its $115-$130. I know, a little pricey, but its a good 40" in diameter. My Firepit.. Is a Burn pile. It cuurently has a Couch, Love seat, Broken skids, junk wood, any cardboard or Copius amounts Paper (Appliances, B-days, X-mas).. Not pretty, but around here we call it a Bon-Fire. I have a dinky little Metal firepit up at the house (Bought from HD) for nights we wanna make Smores or for little gatherings.

I'm going to have to check out my local store and see if they have this.

the "spacing of the pavers at the bottom for air" got me thinking - if I'm digging my pit into the ground (its about 8" in right now)...how does this affect the air flow? If I'm stacking rocks around a foot high around the edge, it will obviously have some pockets of air flowing through the rocks. But could I dig deeper or would that negatively affect the burn and heat it gives off?

 

[smokinj]

There is a new fire pit out in my area that is a boulder drill out for the fire(hollowed out). Can be used with gas or wood. Wished I would have gotten a pic. It is the coolest pit I have ever seen!

 

[CJ-SR4ever]

The way I made my fire pit was digging a hole about a foot and a half down and 4 feet around. Added about 6 inches of sand, and 3 inches of sand extending 2 feet away from the pit all around. Gathered random rocks around from around the yard to do the border with. Nothing special but its safe and gets the job done.

 

[gpcollen1]

I cut a slice out of an oil tank for a large oval fire pit where i camp. Makes a nice fire for cooking on too. Drilled some holes in the side for air flow. I thought about doing a pit at home. Dig a shallow hole and fill with concrete. Mortar fire bricks to make a circle how large I want on the sides- leaving some cracks for some air flow. stack rocks around the outside to finish. It really is that simple. Are there considerations - sure; drainage, burning in the wind, how close to the woods and leaves you are...