David Ross in :

Dooler wrote:

I have fence company installing a retaining wall 2' tall and a fence.
They have done retaining walls before and seem to know what they are
doing, but they are setting the prefab stones at ground level (they
flattened and leveled even with sidewalk) with crushed rock on top
rather than dig down 3" + gravel as per the instructions of
mutualmaterial.com states for manorstones. When questioned, owner
said they will put dirt in front (wall inset from sidewalk a foot).

They just finished first day and got ground level and just started
putting blocks in. Quick recommendation/help appreciated.

This is NOT a retaining wall.

yeah. sounds like bs.
even if not a true retaining wall, i think it needs to extend below grade
to firm earth (under the base rock), else will sink irregularly.


A true retaining wall -- engineered to hold back a slope -- has a
below-ground concrete footing wider than the wall. The depth of
the footing is proportional to the height of the wall. The wall
itself needs steel rods that extend into the footing (placed before
the footing concrete is poured), surrounded within the wall's
vertical channels with more concrete. Where appreciable force from
the slope is expected, horizontal steel rods within the footings
and the wall itself might also be required. This use of steel and
concrete is dictated by the force of the slope behind the wall, and
not by the wall's height; that is, even a low retaining wall
requires this.

Perhaps you are getting a slough wall, which does not support a
slope. A slough wall merely prevents loose dirt and other material
-- slough (pronounced "sluff") -- from trickling or eroding down
the slope. I have a slough wall at the base of the hill in my back
yard. The toe of the slope is at the bottom of the wall, not near
the top. The slope was engineered (benched and compacted) so that
no retaining wall would be needed.

some more web info:
http://www.google.com/search?q=slope...ose%20grade%20
&hl=en&lr=&ie=UTF-8&sa=N&tab=iw

http://www.google.com/search?hl=en&l...ing+rock+wall+

http://www.google.com/search?hl=en&lr=&ie=UTF-8
&q=footing+width+retaining+base+wall+


You can read about my hill and slough wall at
http://www.rossde.com/garden/garden_back.html#hill.

nice. :-)

--
In any case, it is sufficiently steep that I only climb it when truly
necessary. Several times, I have fallen on it, wrenching various parts of
my anatomy. Once I actually fell off it, tumbling over the slough wall at
the bottom.

ow. maybe a mass of shrubs are needed to catch hurtling bodies. :-)

--
When the rain fell, it ran right through the cracks and lubricated the
boundary between the surface and subsoil. The surface (partially pulled by
iceplant that suddenly became waterlogged) slid down the slope, failing to
a depth of about two feet. Thus, everything on My Hill was planted since
the spring of 1993, when the repairs were completed (at a cost almost
equal to what I paid for my house approximately 20 years earlier).
Although the plants on My Hill are somewhat drought-tolerant, I now keep
the soil moist; I water My Hill heavily every other week, allowing only
the top few inches to dry.


it sounds like maybe there could also be an unmixed boundary between
soil types.


that page has good real world experience/info.