2)
DENSE
AGGREGATE
BASE/FREE-
STANDING INSTALLATION:
Mark out the area
of the fire pit and excavate deep enough to
accommodate 6” of well-compacted, dense-graded
aggregate stone, a 1” layer of setting bed sand, and
the 3” thickness of one layer of fire pit wall block
that will be buried as the footer course. Make sure
the excavated soil surface is smooth and level.
Thoroughly compact the soil surface. Geotextile
(Mirafi 500) is recommended as a separation
membrane on top of the soil surface and up the sides
of the excavation to help maintain the integrity of
the dense-graded aggregate stone base, especially
when clay soils are present.
Shovel in the stone for the base and spread it evenly
in layers 2” thick. Carefully compact the stone base.
For best results, use of a vibratory plate compactor
is recommended for this purpose. Repeat this process
until the stone base is 6” deep. Before compacting
the final layer of stone, use a straight edge and level
to see if the surface is smooth and level, then
compact and check again. If the surface is not level
and smooth, scratch the surface with a rake, smooth
and level it, and compact it again. If the fire pit is
being incorporated into a paver installation set the
base course along with the pavers as they are being
installed.
For the 1” sand setting bed, lay two or more pipes
with an outside diameter of 1” on the stone base.
Place a couple of shovelfuls of coarse, washed
concrete sand between the pipes. Then using a
straight edge, such as a 2”x 4”, drag it across the
length of the pipes pushing and smoothing the sand.
Repeat this process until the entire surface is covered
with a uniform layer of coarse concrete sand 1” thick.
Pick up the pipes and fill in the void left by the pipe
with sand, smoothing it with a broom or mason’s
trowel.
Lay the first course of fire pit wall block, setting the
units tightly together and being careful to lower the
block straight down on to the sand. Do not drop the
units into place or set them on edge and let them
flop down. Either method will result in an uneven
base coarse that will cause structural unevenness in
the fire pit wall. If any block are out of alignment or
the circle is distorted, tap the blocks into place with
a rubber mallet or dead blow hammer. The interior
of the circle created by the base course should be as
close to perfect as possible. The exterior dimension
should vary due to the irregular face of each block.
Once the first course has been aligned, seat the
blocks into the sand by striking them in a downward
motion on the exposed horizontal flat side of the
block with a dead blow hammer or rubber mallet.
Check the top surface of the blocks to make sure
they are level from front to back, side to side, and
from block to block around the circle of block and
spanning the circle of block equatorially from one
side to the other. The block should settle into the
sand about 3/8”.
Continue to page 6.
CALL BEFORE YOU DIG!
It is your responsibility to notify the utility
companies a few days prior to digging so that
they can mark out any underground lines. For
your convenience, dial 8-1-1- nationwide and
be prepared to describe the scope of your
project. Avoid injury, expense and possibly a
day in the dark.
For more info, visit
www.call811.com.
| 4 |
| FIRE PIT INSTALLATION GUIDELINES
ephenry.com | 800-444-3679