how to build a safe firepit

[Qqueen]

I want to build a custom fire pit in my backyard but I have heard that there are some stones which explode when heated. Is there anyone who can give me a list of stone types to avoid when building a fire pit? It must be safe because I have kids around.

[jtilk]

just avoid the ones packed with explosives

[MinneSmoka]

I made a temporary campfire ring from a some wet river rock and after it got hot enough a couple cracked and popped. Some rocks are porous (lava rock) and can have moisture in them, when hot enough I think it's the internal steam that splits them. It didn't really explode but I suppose some shards could fly.
Lava rock that is thoroughly soaked shouldn't be used until dried out. So I've been told.

[DATsBBQ]

Line it with fire-bricks. You can get them at places that sell wood stoves. Conversely you could use cinder blocks but they will crack over time.

[Boots]

Lined w firebricks is right, but they also make a fireproof or fire resistant mortar. The regular mortar will break down under the heat over time. I think it is called refractory mortar.

http://www.ehow.com/how_7898096_make-fi ... ortar.html
http://www.fornobravo.com/forum/f8/diy- ... -5764.html

[esugrad97]

I built one, this past spring, and I just used limestone that I picked up along the side of country roads. I live in Kansas, though, so it's pretty easy to find.

[dub']

If you use firebrick make sure it stays dry.
Water will flat ruin firebrick in short time.