Firepit question

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?

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....

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

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

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

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.

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....

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.