By Michael Swiderski, Ph. D.More in Blog Cabin
With the screwdriver or wooden stake still in the center, measure out a smaller radius from the center. Pull the string tight to this distance and create a small trench, which will outline the inner fire ring stone circle.
Mix up a small batch of cement mortar and sand, following the instructions on the bag. Fill the bottom of the circular trench with the cement mortar and place the biggest stones in the mix. Continue to fill the trench with mortar and stones. Pull the 3' radius string to confirm distance from the center. Place smaller stones in between the largest stones to fill in gaps of the fire ring.
Using bags of silica sand or wheelbarrows full of playground sand, carefully fill the inner ring with the sand of choice to approximately a 4” depth. Be mindful not to disrupt the large stones, which are curing in the cement mix.
Trench a circle for the outer perimeter ring and fill it with stones set in mortar. This time, though, the stones are smaller in size (8” to 12”).
Fill the perimeter ring with approximately 4” of sand. Again, be careful not to disrupt the stones setting in the mortar. Use a rake to level the surface and a hand trowel to work the outside edges and force the sand into the rocky cracks.