Build Your Own Backyard Fire Pit

Step 8 Fill the Pit

Fill the pit with 6 inches of gravel, which will help support the first two courses as they set up. Glue and lay the third and fourth courses, continuing to stagger the joints.

Insert the iron campfire ring into the circle. Adjust it to sit even with the top of the block wall. Fill any space between the ring and the block wall to the top with gravel.

Work quickly and only in a small area at one time; masonry adhesive sets up quickly.

MORE: Wide World of Adhesives

Comments

[ddpedersen]

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]

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]

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]

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]

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]

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. 
 

[Covert Koala]

 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.