Firepit question

[Stegman]

Thinking of building a backyard firepit this spring to replace my old, worn firebowl. I want to keep it simple and cheap. Don't want to buy one of those pricey kits. I was planning to just get a bunch of pavers, set 'em up and throw some gravel down inside.

Here's my question: How important is a metal ring? I see those are part of the kits, but they seem somewhat dubious to me. Is one really needed to protect the pavers from the heat?

 

[ScotO]

You don't need any metal ring, it will rust.....
Heck, you don't even need pavers if you have an area where you can get fieldstone from. DO NOT USE ROCKS FROM A STREAM.
We were just discussing firepits the other day, my pit is the keyhole design I've shared pics of many times here on this site....

https://www.hearth.com/talk/threads/the-keyhole-firepit-comes-to-life.106105/#post-1387211

https://www.hearth.com/talk/posts/1132489/

https://www.hearth.com/talk/threads/the-best-things-about-burning-outside-in-the-summer.86946/

 

[homebrewz]

Its not whether or not the rocks come from a stream, its that they can't be sedimentary rocks. They have pore spaces in which water and air can reside.. when they heat up, they explode. For this reason, I wouldn't use pavers for certain parts unless they were heat rated. Look for igneous and/or metamorphic rocks like granites and gneisses.

 

[ScotO]

I agree that the make-up of a rock has alot to do with the explosion factor, but I ain't gonna make a firepit out of rocks that have been submerged in a stream for hundreds of years.....that rock is gonna have water in it, and you heat up a rock that is saturated in water its gonna crack or possibly explode on ya......not worth the risk.....

I've used fieldstone off of the mountain for many a firepit, and aside from the occasional crack, have never seen one explode....

 

[keninmich]

I made a simple fire-pit last summer.
I bought 4 9ft. long railroad ties and made a square. I drilled holes in them and drove 3 foot lengths of re-rod in them so they don't move.
Then i bought one of those metal rings and sunk it halfway into the ground. We have plenty of room for a couple of chairs inside the box and lots of room to stack some wood for the fire.
I covered the ground with some weed fabric and some rubber mulch.

Wrestling the RR ties was more work than i anticipated (they weigh well over 200 lbs. each) but it only took a day to do and it turned out great.

 

[DevilsBrew]

What type of bricks are you using for the keyhole fire pit? Would using something like firebrick in place of the stones be an option to retain the heat?

I love the design because it is so flexible.

 

[ScotO]

What type of bricks are you using for the keyhole fire pit? Would using something like firebrick in place of the stones be an option to retain the heat?

I love the design because it is so flexible.

I used nothing but natural fieldstone for my pit, harvested off of the mountains around my house. You certainly COULD use firebrick for the pit if you wanted. The real beauty of this pit is that you can be cooking on it in a matter of 20 minutes or so with the offset keyhole design....

 

[lukem]

Pavers will crack. They are made from the same stuff as concrete blocks and those crack after a few fires.

You could build it with pavers and line it with fire-brick for some protection, but I'm not sure how well fire-brick will stand up to the elements and repeated freeze thaw cycles.

I'm sorry I probably just gave you more questions than answers...

I'm not sure I'm completely convinced that a piece of granite harvested from a creek bed is a failure waiting to happen. If water can get in it can get out. Sedimentary rock is a different story because it forms at low temps with a lot of water in the process. Last time I checked there isn't a lot of water in liquid hot magma so I doubt there is any trapped inside a rock.

 

[Adios Pantalones]

Firebrick won't hold heat better than stone. The reason that people use it for specific applications is that it's a regular shape for building, holds heat, and resists a known amount of heat/can be heat through quickly without stress cracking. Stone and firebrick have similar densities, and should have similar specific heat.

I have plenty of firebrick in my yard, but will be slapping together a firepit with field stone from my property.

Pavers are liable to crack/disintegrate under good heat.

 

[ScotO]

I like the natural and aesthetic look of stone.....I'm not particularly fond of man-made masonry products.
..

 

[DevilsBrew]

The keyhole fire pit is awesome.

I'm at the learning stage of fire pits. I'm trying to figure out the best way to retain heat and use less wood but keep the fire experience status quo going.

 

[nate379]

I made one a few days ago in about 15 mins. Cost me maybe .50 for electricity and welding wire.

Took a 55 gal drum, cut it in about 1/2, welded the ends together so I have two open ends and the lids in the middle. Sits about 2ft high. Worked great all weekend. Kept a fire burning non stop for 4 days on maybe 1/8 cord of wood, if that. Open fire would have ate that much wood in a day or two.

 

[jebatty]

I agree a metal ring is not needed, but the ring or equivalent serves the function of concentrating the heat so the fire burns better, shielding the fire and coals somewhat from the wind, and reducing flying embers. I bought one of the kind that you might see in a state park/campground which has a very heavy metal grate for cooking or grilling. The grate slides up and out of the way for fires without the grate, and the grate is really heavy duty -- you could stand on it without bending it. Rust is a non-issue with this heavy duty fire ring.

 

[DevilsBrew]

I saw where someone used a perlite mixture for insulation on a fire pit. What would be the best type of insulation to use?

 

[ScotO]

I saw where someone used a perlite mixture for insulation on a fire pit. What would be the best type of insulation to use?

don't take this the wrong way as I'm not trying to be ignorant, bit I think you are putting too much thought into this firepit. You are going to lose a ton of heat at the top of the fire, so insulating the bottom or sides of the pit isn't going to help. My opinion on a fire in the backyard is the bigger, the better!!

Now when we cook on the pit (which is quite often as you will see on here), I use the good stuff. White oak, hickory, cherry and applewood to name a few. You cant get a better flavor in meats than over a smoldering fire!!

I usually save lesser woods (punky stuff, knarly branches, uglies, etc) for building "fun" fires. Heck, I like putting pine and such in the outdoor pit because it pops and crackles with lots of sparks....... that's what makes the firepit fun!!

 

[DevilsBrew]

It's cool, Scotty. I just like playing with fire. I went through a lot of firewood last time and I would like to cut that back a little. I totally agree with you about the use of a fire pit. It is supposed to be fun interaction.