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 AREA. HOWEVER 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 TerraceWall™ 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 the hose. 

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 the footing.

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 3).

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 be also.

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 complete. 

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 the curb. 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 correctly.

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 it to 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 1-1½". 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 work with.  

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 is good, 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 hose

*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 tamper, 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 and 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.