I needed a retaining
wall. But I didn’t
want to abuse my back by
schlepping around landscape
blocks. Plus, I didn’t
want to bust the bank buying
good-looking blocks. So after
accessing my internal carpentry
database, I came up
with a solution: a wood foundation
built as a retaining wall. I’ve
built dozens of wood foundations
(yes, made from treated wood for real
basements under new homes), so this
was a no-brainer—super easy, attractive
This 32-in.-high, 32-ft.-long wall was built
in one fairly laid-back day by me, Brad and
another friend of mine named Bob Cat (meet
him in Photo 7). The materials cost $500, plus
another $500 for Bob and his operator, who supplied gravel and some extra topsoil for fill.
Having Bob involved meant there was very
little shovel work. And Brad appreciated
having Bob there almost as much as I did.
The skeleton of the wall is a treated wood,
2x4 stud wall clad on both sides with 1/2-in.
treated plywood. It’s held in place with 2x4
“dead men” assemblies buried in the backfill. The dead men
are 2x4 struts
bolted to the wall
studs and anchored
to a perpendicular
2x4 sleeper (see Figure
A). The weight of the soil
on the dead men anchors the
wall against the backfill pressure. It’s important
to locate the bottom of the wall below
grade a few inches so the earth in front of the
wall will anchor the base in place.
Get the right stuff
Ordinary treated wood will last a good long
time depending on soil conditions, although
wet sites with clay will shorten the wall’s life
somewhat. I used ordinary treated wood from
the home center, and I figure the wall will last
at least 20 years. To build a wall that’ll last forever,
use foundation-grade treated wood, the
material used for basements. It’s usually
Southern yellow pine, a very strong softwood
that accepts treatment better than most, and
contains a higher concentration of preservatives.
You may find it at lumberyards where
contractors shop. Or you can special-order it
from any home center or lumberyard, although
you’ll pay a premium.
Choose nails rated for treated wood: 16d for
the framing and 8d for the sheathing. Use 3-in.
construction screws for standoffs and dead
men connections—again, ones that are rated
for treated wood. You’ll also need a box each
of 2- and 3-in. deck screws for the trim boards.
Figure A: Wall Anatomy
No matter how large your wall is, it should have these basic elements.
Prepping the site
I had a gentle slope to retain,
not a huge hill. This 32-in.-high
wall is designed to hold back a
gentle slope and is good for
walls up to 40 in. For walls 40
to 48 in, place the studs on
12-in. centers and keep the rest
of the wall the same. Don’t
build the wall more than 48 in.
high—a taller wall requires special
Do the digging with a shovel
if you wish. The trick is to dig
halfway into the hill and throw
the soil on top of the hill. That
way you’ll have enough fill left
for behind the wall. The downside
is that if you hand-dig,
you’ll also need to dig channels for the
2x4 struts and sleepers (see Photo 5).
It’s much easier to hire a skid steer
(Bob) and his operator to dig into the
hill and then cut down a foot or so
behind the wall to create a shelf for
resting the dead men. Expect to pay a
few hundred dollars for skid steer services.
The operator can also scoop out
the 12-in.-wide by 10-in.-deep trench
for the gravel footing, and deliver and
dump a 6-in. layer of gravel into the
footing. Then you’ll only need to do a
bit of raking to level off the trench. A
yard of gravel will take care of 50
linear feet of wall. If you have extra
gravel, use it for backfill against the
back of the wall for drainage. Have
Bob and his operator return to fill
against the back side of the wall and
do some final grading.
Get the footings ready
Fill the trench with gravel. Any type will do, but
pea gravel is the easiest to work with. Roughly
rake it level, then tip one of the footing plates on
edge and rest a level on top to grade the footing
(Photo 1). Use the plate as a screed, as if you’re
leveling in concrete, and you’ll get it really
close, really fast. Try to get it within 1/4 in. or so
of level. Offset any footing plate joints at least
2 ft. to either side of wall joints. To drive down
the plate until it’s level, stand on it as you pound
it into the gravel with another board, occasionally
checking it with a level. If you can’t drive
the board down to achieve level, scoop out shallow
trenches on either side of the footing plate
with your hand. Then there will be a place for
gravel to flow as you drive down the plate.
Frame and set the walls
Frame the walls in your driveway or on the garage
floor. The walls are very light, so you can carry
them a long way if you need to. Build
them in sections, whatever length
you like, and screw the end studs
together at the site. Leave off the
sheathing for now. Snap a chalk line
1 in. in from the outside of the footing
plate to align the walls (Photo 2).
Place them, screw the joining studs
together with four 3-in. construction
screws and screw the wall plates to
the footing plates in every other stud
space with 3-in. construction screws.
Plumb, straighten and brace the
walls from the front side and then
add the tie plate. Make sure to seam
the tie plate joints at least 4 ft. away
from the wall joints.
Sheathe and waterproof the walls
Set the plywood panels in place one
at a time. Draw and cut 1-5/8-in. x
3-5/8-in. openings spaced 6 in. down
from the underside of the top plate
and directly next to every other stud.
Nail each panel into place with 8d
nails spaced every 8 in. before
moving on to the next one. Cover the
outside with ice-and-water barrier
(Photo 4). The adhesive won’t hold the
barrier in place, so staple it as
needed. Cut off the excess at the top
and cut out the strut openings with a utility knife.
Add the struts and sleepers
Slip the struts through each hole.
Prop them up so they're close to
level, either by piling up dirt or supporting
them on chunks of scrap
wood. Screw each one to a stud with
three 3-in. construction screws.
(Predrill the holes to prevent splitting
since it's so near the end.) Screw the
sleeper to the other end of each strut
with two more screws.
Skin and finish the front
Before you can finish the front of the
wall and backfill behind it, you’ll
have to remove the front braces. So
prop up the dead men to keep the
wall near plumb while you finish
the front. Cut the plywood and nail
it on, orienting it vertically to the
front so the exposed grain will match
the 1x6 boards applied over them.
Add the 2x8 cap, keeping a 1-1/2-in.
overhang at the front. Screw it to the
tie plate with 3-in. deck screws.
Screw the 1x6 treated boards to the
sheathing with 2-in. deck screws.
We spaced our boards every 1-1/2
in. using a scrap 2x4 as a spacer.
Don’t trust the spacer for more than
a few boards at a time. Occasionally
check a board with a level and make
any necessary adjustments.
Back to Top
Backfill and finish
Plumb and brace the wall from the
back by nailing braces to the top cap
and staking them on the hill. Prop up
every other strut and the sleepers
with scraps of wood or the fill falling
on the struts and sleepers will
force the wall out of plumb. Backfill
first against the front of the wall over
the footing to lock the wall base into
place, then fill behind it. Then fill
over the sleeper, working your way
toward the wall itself. The object is
to lock in the sleeper before the fill
pushes against the wall. Once the
backfill is in place, it’s a good idea
to run a sprinkler over the fill for
several hours to make it settle before
you remove the braces.
If you like the look of your wall,
you’re good to go—no finish required.
The treated wood will weather from
green to gray in a year or two. We applied two coats of exterior butternut color stain to ours.