DIY Fire Pit and Patio

I first measured and marked the layout for the patio fire pit. This is where the pool was for several years.

I made a homemade water level, which does the same thing as an expensive laser level, but this one was built with scraps.

Let the digging begin! I dug down 7 to 9 inches, depending on the level of the sod.
 
I then dumped crushed stone in the area, then leveled and compacted it so the depth of stone averaged about 5 inches.
 
For the next layer, I added 1 to 2 inches of sand.

I then divided the area up like a pie and leveled one section at a time. The level of the sand determines the final level of the patio, so getting it right was very important.

I ran string from stake to stake on the level lines I made earlier. I then set a steel pipe in the sand under the string and shifted it up or down to the level I needed. After tamping down the sand, I used a board to screed the excess sand from the top.

Once the sand was leveled, the fire pit was ready for pavers. I used about 700 pavers. First, I started with the fire pit stones, and then I added a ring of pavers. I was careful to make sure they were laid in a true circle. Note that the center stake has been replaced with pipe so that a guide string can rotate freely around it.

I continued outward, laying the pavers and leveling the outer edge by hand. I quickly learned that you must check the angle of every single paver to be sure it has the right orientation.
 
Next, I brushed some sand into the cracks to keep them from moving too much during the next few steps.

I placed edging around the outside, and then leveled up the fire pit. Then, I glued the center pavers together. The fire pit blocks were about $1.50 each.

I hosed out a lot of the coarse sand that was between the pavers, making room for the good stuff. I then applied a very fine paver-locking (polymeric) sand. It has a flexible glue that is activated by moisture, which lasts several years. I used the same stuff on a patio in the front of my house about 4 years ago, and it's very resistant to weed growth & washout.

Four weeks and about $1,200 later, we had our new fire pit & patio! The patio itself only cost about $800, but the patio furniture and plants were about $400.