The
foundation is the most critical element of sand setting and includes the
features of solidity and durability. A sound substrate is the skeleton
for stability.
1. For a solid sand set, a soldier course is advised. By soldier course
we mean a mortared solid frame. This can be achieved by an existing wall
or embedded frame of stone or cement. The purpose is to hold the sand
and material in a solid composition.
2. The foundation laid within this frame is composed of a minimum of 180/280
mm of crushed stone base course which may be dry mixed with different
types of gravel, clay or cement and is compressed smooth with a vibrating
plate compacter until firmly compacted. This is followed by a layer of
60/90 mm of course sand, leaving a depth of the thickness of the specified
stone plus circa 15/20 mm (for compacting).
3. Porphyry is available in cubes or paving tiles of random lengths or
fixed dimensions and offers extreme durability. 30/60 mm material is applicable
for pedestrian use and light motor vehicle use such as driveways. The
thicker material is applicable for heavier more sustainable usage.
4. Set the desired levels (drainage of 1.5/2 % drop per meter minimum)
with strings. Place the pavers or cubes on the sand at a distance approximately
10 mm from each other and set lightly into place insuring a firm set in
the sand. Remember that the use of the measuring strings helps to insure
both the alignment of the stones and the levels. With square tile it is
recommended to use crossed strings in order not to lose the square alignment.
5. With brick or other gauged material, levelled or screed sand is advised.
The setting proceeds from the brick forward to the sand.
6. With natural, ungauged stone, screeding is not required and the setting
progresses from the stone to you, with the setter in the sand bringing
the material towards them, adjusting the sand level to the thickness of
the stone. The top level of the stone being set at 15/20mm above the desired
finished grade.
At this point you have the option to sand the joints or use dry
mortar.
Sand:
Sweep a medium coarse sand over the stone into the joints
Mortar
Set:
This is done only in dry non-freezing conditions.
Sweep a dry mixture of 2 parts cement and 3 parts sand into the joints.
(Variations of mixture due to regional conditions and practices within
Marble Institute of America guidelines are acceptable.)
1. A plate compacter is now used to set the stone into the sand, firmly
setting the material against the soldier course, locking the stone firmly
together and compacting the sand or mortar mixture completely into the
joint. Using long 6-8 foot levels to establish the finished grade and
level, finish levelling and smoothing with the compactor.
2. If using mortar mixture, soak with water to set mortar.
3. Use a pole squeegee to clean stone and adjust grout or sand levels
removing any excess grout material.
4. Finish cleaning with a thick firm wet construction sponge making sure
to remove all residues.
5. After the mortar has set and is dry, a light acid cleaning is advised.
|