THIS DISPLAY AS SEEN HERE IS
GONE AND HAS BEEN REPLACED. CLICK
HERE TO SEE THE NEW TECHO DISPLAY WHICH REPLACED WHAT WE ORIGINALLY DID IN THIS
BECAUSE THIS PAGE PROVIDES GOOD AND PRACTICAL INFORMATION REGARDING PAVER &
RETAINING WALL INSTALLATION IT WILL REMAIN
(all photos are thumbnails, just click on it to enlarge)
Every paver or retaining wall project begins with the excavation. Depending on
the size and scope of the job, the excavation can be done by hand or by machine.
For a standard patio or sidewalk, you should excavate eight (8) inches
below where the finished height of your paver is going to be.
For areas which will experience vehicular traffic, the excavation
needs to be 12 - 16 inches. For retaining walls, the base should be
four to eight inches deep, depending on the height and application of
the wall. It
is obvious from the pictures which excavation method we chose.
Once the excavation is complete, modified stone or quarry blend is installed.
For foot traffic areas (patios, sidewalks), a minimum of four inches of stone; for vehicular traffic
areas, eight to twelve inches of stone. The stone is then compacted using a
vibratory plate tamper or mechanical roller. That fine looking guy running the
tamper is yours truly.
Notice the black fabric-like material laying around the edge of the stone.
That is soil stabilization fabric. It is installed over the soil
BEFORE the stone is placed. This keeps the stone from sinking down into the
soil. This is especially important in wet areas (like we have), and areas which
will experience vehicular traffic.
The display we are creating contains both a retaining wall and concrete
pavers (for the wall, we have chosen
in the color Dakota Blend, the pavers will be Coventry
Stone I™, in Harvest Blend). Our display encompasses two different levels so we
need to install the wall first. The wall will then act as an edge restraint for the
pavers on the lower side, and once backfilled against, will allow us
to work on the upper level simultaneously.
Notice the garden hose stretched out on the ground. We used that to
determine the exact position and shape of the wall. Using the hose
lets us see how different locations, radius of the curve, etc will
look before the actual placement of the wall units. Once we are
satisfied with its location, we used upside-down paint to mark the ground and removed
Then, using a site level, we
determined where the TOP of the finished wall is going to be. We then set up a
series of grade pins (which follow the shape we made with the hose) and marked each pin accordingly. We then ran a string line
around each pin the full length of the wall. This allows us to
determine the grade and height of the sub-base. We then cut away the excess
soil stabilization fabric.
With a tape measure, we measured down from the string line. The
height of our wall will be 21" (TerraceWall™ is six inches high, so we
will use 3 courses plus the cap course). We will
adjust the sub-base to insure that we have 21" below the string for the
entire length of the wall. For a job like this, the depth of the sub-base will
be four inches. However, on higher walls, six to eight inches may be required.
Once we have achieved the proper heights, we will begin installing the wall.
Part of the wall will run along the side of a sloped parking lot. If you look
carefully at picture 1, you can see the distance between the string line and the
parking lot decrease as you go left to right. Segmental retaining walls are
designed to be LEVEL, regardless of the pitch or slope of the area surrounding
them. When facing a situation like this, the wall can either step up or step
down (depending on your view). This "stepping" process can occur above or below
grade. It has
always been my contention that retaining walls look best when they are level
along the top, which means we will have to step the wall below ground as part of
Although it is difficult to see, picture 2 shows three different levels of
footing. The wall will run from a height of nine inches (1 course + 1 cap) to 21
inches (3 courses + 1 cap). However, visually the wall will appear to be the
same height. This is easier to see now that the wall is being installed (picture
The base course of any segmental retaining is the most important. It must be
level and plumb. Because these retaining walls are dry-stacked (no mortar
joints), each additional course follows the pitch and direction of the base
course. If the base is "out of whack" the entire wall will turn out to
It is almost
impossible to get the stone sub-base perfect. So, to compensate for this, a
thin layer of stone dust or screenings can be installed on the footing. This allows the installer to adjust the base course of
block to insure levelness. Use a torpedo level to check each individual
block, adjusting front to back and side to side, and then a four foot level
to check a run of block. If something is out of level, fix
it immediately. If you do not, you will find yourself taking sections of the
wall down later, because what may be as little as 1/8" out on the base, can
quickly become 1/2", even 3/4" out as you build the wall. That may not sound
like a lot, but when you attempt to cap the wall, the caps will rock, not
fit correctly, and you will immediately see that you should have fixed it to
begin with. Trust me, I
know. These are the types of
projects that other people's mistakes can greatly benefit you.
Once the base course of block is installed, you can then begin stacking the
wall units to the desired height. TerraceWall™ locks together with a small tab
located on the underside of the back of the unit. Simply place a block on top of
the lower course and pull forward. As each subsequent course is installed, each
block should be filled with clean stone. This helps to further stabilize the
wall. We will also install 6" - 12" of clean stone behind the wall for
drainage. Then we will backfill with dirt to the top of the wall. 90° corners are easy to create using the TerraceWall™ corner unit.
Installing, cutting and gluing the caps down is the final phase of the
actual wall construction. Once that is complete we will begin the backfill
process and prep our sub-grade for the pavers which will extend from the front
of the wall facing Evergreen Avenue to the curb line. Phase I is
Phase II is the first of two sections of interlocking pavers. But
unlike the retaining wall, the pavers need to have a pitch for water to
move. Since we are working along the existing curb line, the height of
our pavers is already set on one side. We will pitch the pavers so
that the water will run into and along the street. If we were working along the back
of a house for example, we would pitch the pavers away from the house.
A simple rule of thumb for
determining pitch is one inch per ten foot. We have 17 feet at the
widest point, and five feet at the narrowest. Using the one inch per
ten foot rule, we will pitch the area 1.5 inch in the widest section
and approximately .5 inch in the narrow area.
Using our site level we first determine the height along the top of
This allows us to determined the height of the pavers on the
"high end," the area starting at the wall that will pitch
towards the street. If you do not have access to a site level, this can be done using a
string line and line level. To do it that way, we would set a pin
along the curb and mark it where the top of the paver will be (keep in
mind that we will be tamping the pavers once the installation is
complete, so add 1/4" to 3/8" to your mark) . Place another
pin at the wall and run a string line between the two. Using the line
level, adjust the string until it is level. Once this is done, measure
down 1inch (or whatever the pitch necessary for your project) on the pin near the wall, and move the line up
accordingly. Just that simply you will have the right pitch.
Of course, we have access to all the
fun equipment and tools so we will do basically the same thing using
the site level. We then set up a series of string lines so we can
insure that our sub-base not only follows the pitch that we need, but
is also the right depth. Remember, whatever direction
or pitch the sub-base goes, so will the pavers. That is why it is so
important to make sure that this part of the project is done
Once all our lines are set, we brought
in the modified stone, placed it at the correct height, and using the
plate tamper, compacted the base. Remember, there is no
such thing as over-tamping. Continue to tamp the base until the police
are called on you for disturbing the peace. Well, maybe not that
long, but make several passes over each area. Think of it in
terms of your own house. You wouldn't want your house on an inadequate
foundation. This is the same concept. The better the base, the better
the job. We are now ready to screed the sand and lay pavers.
One consideration that needs to take
place at this point is an edge restraint. Pavers need to held together
by something. In our case, we have the retaining wall on one side, and
the concrete curb on the other. Most jobs do not. The two most common
edge restraints being used is a pre-fabricated heavy duty plastic edge
or a mixed and placed on site concrete edge. There are several
manufacturers of the plastic edge throughout the industry, we handle The
B.E.A.S.T.™ by Brickstop. The plastic edging is installed
on the stone base either before you screed the sand and begin to
install pavers or against the edge paver once the installation is
complete. The concrete edge is installed against the edge paver after
the installation is complete.
As far as the sand is concerned, concrete sand is the recommended choice. The
reason for this is that if you were to look closely at concrete sand and compare
mason or bar sand, you will notice that concrete sand is much coarser. Once the
pavers are installed, we will run a plate tamper over them to "lock the job
together". At the same time the pavers are being forced into the sand, some of
the sand underneath is being forced up into the joint. The coarser sand creates
a much stronger interlock.
The sand should be placed at a depth of 1-1˝". Keep in mind, the sand
is acting as a leveling base. Too much sand (2" or more) could
create a "wave-like" appearance in the surface of your job as the
tamper may push some of the pavers down further than others. To achieve the
proper depth, we are using "screed rails" which in reality are one
inch electrical conduit, available at any electric supply yard. They are
available in many lengths and can easily be cut to fit your particular job.
The rails are placed directly onto the stone base, and then the sand is
placed on top. That is why it is so important to have your sub-base accurate. Using a 2x4, you "pull" the sand across the top of the
rails. Notice the lines left in the sand once the rails are
removed. These can easily be fixed with a trowel, or pulling the back of a
push broom along the top of the sand, leaving you with a smooth layer of sand to
We have chosen Coventry Stone I™ as our paver for this area.
Coventry Stone I™
consists of two sizes, a 6x6 unit and a 6x9 unit. For this project, we have
elected to use the 6x6's as a border. I feel installing a border
of either the same type of paver you are using or even a different paver all
together, gives the job a much more "finished" look. Often times a
contrasting color is used to set-off the border. However, a border
is not necessary or required. That decision will be yours to make.
In many cases, the actual laying of the pavers is the easiest part. But there
is one aspect of the installation process which is absolutely crucial - pavers
must be laid SQUARE. Not necessarily in a square shape, but square unto
themselves, like a wall needs to square. Pavers are designed to lock together in a very specific way
and no amount of praying or cursing at them will change that. So it is extremely
important to begin the laying process correctly. If you look carefully at
Picture 2, you will notice a tool called an angle guide or paver square. This tool is adjustable
and allows the installer to set up perfect 45° or 90° angles depending on the
paver and pattern being installed. Once the correct angle is established, the
installation process moves along rather quickly.
However, since most
people do not have this tool, there is another way. It is called
the 3-4-5 triangle method. From a corner that you can work out from,
measure along one side three foot and along the other side four foot.
If you are square, the intersecting line should be five foot. If it is
not, adjust the position of one of the two sides until it is. Once a
square line is established, snap a chalk line in the sand and start
laying your pavers off of that line. If you fail to do this, and just
begin laying pavers "by eye" you may find that at some point
the pavers stop fitting together correctly. When that happens, you
have just wasted "X" amount of hours because now you have to
pull ALL of the pavers you installed up, and start all over again.
Once again, trust me when I say that this is not a lot of fun.
There are no great magic tricks I can offer you as far as installing pavers
are concerned. Its pretty simple, pick them up and put them down. But, pavers
are heavy (approx. 28 lbs per square foot) so, I do suggest this, buy hoagies
(steak works even better) and beer and con your friends into helping you. A
30 pack of Coors Lite™ is
only about $17.00, and worth every penny.
Only one person should be doing
the actual laying of the pavers, but it is very helpful having people on site
"feeding" you the pavers. As the installation progresses, both the
feeders and the installer can walk out on the pavers. One person feeding
two is much better. An inexperienced installer could easily do 400-600 a day
with a couple of helpers (assuming of course the sub-base and sand are correct). Some professionals will do up to 1200 square feet in a
day. If you are stuck by yourself, you'll be lucky to get 200 square feet done
and your back and knees will pay for it. Curved areas will take longer then straight
or angled areas.
In projects that do have borders, I have found it much easier to basically
ignore the fact that a border is going in on the opposite side when laying
"the field.". Lay as many full pavers as you can right up to the edge. 99% of all paver job will require some type of cutting,
especially curved areas. To cut the border in on a straight run, lay whatever
paver you are using for the border on top of what has already been installed at
each end of the area to be bordered. Take a chalk line and snap a line
on the installed pavers at the bend of
each border paver. You now know exactly where you cuts have to be made. Pull the
existing pavers up and cut them. Return them to their original spot and the
border paver should drop right in.
Curved areas are a little trickier but the concept is the same. However, this
time the chalk line is obviously useless. One neat trick I've seen done is the
use of flexible one inch pvc pipe. It does require more than person to pull this
off, but basically you lay your border paver on top, just like before. This time
use the pvc pipe to bend around to meet the other border paver. With a crayon or
marker, marker the pavers already installed. Pick them up, cut them and replace
them. Once again, the border should drop right in. Once you made all of your
cuts, you are almost home free. This same trick could be done with a garden
hose, but be very careful when marking the pavers you do not move the
*In the final step, we need to sweep sand into the joints. Once again
we will use concrete sand and basically you just take a shovel and
literally throw it across the surface. With a push broom
sweep it around. You will notice immediately some of the
sand disappearing into the joints. Continue this process until you
have a thin coating of sand across the entire surface of the pavers.
Cover the surface of the pavers with the same or similar fabric that
you placed under the stone. Now run the plate tamper across the pavers to "lock"
them in. The fabric insures no scratching, scuffing or chipping of the
paver surface. Do not worry about breaking the pavers with the plate
they are 8000 psi, they can take it.
Repeat this process at least two times for walkway areas and at
least 3-4 times for vehicular traffic areas. After the final tamp,
continue to sweep sand into the joints until no more will go in. Sweep
off the excess sand and your job is finished. Crack open a cold one
(or two or six).
Here is what we started with, and here is what we
ended up with. Pretty
impressive, huh? The hardscaping phase of this display is complete for
now. An additional paver walkway will be installed later. Special
thanks to Jeremy George, John DeRosa and Matt Berkheiser of EP Henry
for braving the weather (it was real cold a couple of the days) and
installing both the retaining wall and the pavers, and to Nick Furfari
of Think Pavers, who even though he was nursing a hangover, assisted
us in grading and prepping the sub-base. From our staff, Alan Ramsey
Bob Meachum Thanks to
everyone for a great job done. Oh, by the way, Woodbury Cement
Products as a company does not promote the consumption of alcoholic
beverages, but after doing a project like this, you may!
*Since the building
of this display, polymeric sand (we sell
Joint Set by SRW) has replaced concrete sand as
the sand if choice for sweeping into the pavers. Polymeric sand
hardens after water is applied to it. This helps prevents weeds and
insects from making a mess off your pavers.