David E. Ross wrote:
....
A well-built wall -- either a perimeter wall or a retaining wall --
should have weep holes to allow for drainage. If your perimeter wall
does not have weep holes, you should get a good masonry drill bit and
create some.

if it's heavy soil behind they might not
do much good. in clay the footings and back
fill become even more important. in areas
where there are frost/thaw cycles it becomes
triply important.


To make the clay less sticky and more easy to dig, broadcast a generous
amount of gypsum over the area, perhaps a centimeter (1/3 inch). Let
the rain rinse it into the soil. Repeat at least once.

A retaining wall needs to be engineered correctly. This is generally
NOT a do-it-yourself project. There are issues about footings (depth
and width), anchoring into the slope, amount and size of rebar (steel
rods), grout, etc.

agreed. if you're going to do this do
it well because if you do it wrong and it
fails it costs a lot of effort to do it
all over again correctly.


A retaining wall is not a slough wall. I have the latter at the foot of
a slope. It does not hold the slope but merely prevents small amounts
of loose soil from reaching the flat area of my garden. When my slope
failed, it overtopped the slough wall. It cost over $150,000US to
regrade the slope; it would have cost twice that to use a retaining wall
to hold the slope.

holy crap! that could buy three to five houses
in any of several local small towns around here.


songbird