The layout: Paving brick come in a variety of shapes, colors, textures, sizes and thicknesses. These bricks can be used for a multitude of different projects and an even larger amount of design concepts. The choices are almost indefinite, but for the first time user, it is recommended that the Do-it-yourself homeowner follow these simple rules for easier installation:
- Use a smaller squared and/or rectangular brick,
- Design your project with straight edges, no curves (reduces cutting
of the brick),
- Choose brick that are all the same thickness (don’t mix brick types),
- Keep your overall design in square or rectangle shape.
The cutting of the paving brick can be difficult. The more cutting you have the longer and harder the installation will become. It is possible to minimize or even to completely eliminate the cutting of the brick by following the about suggestions.
|A cross-section of a typical brick installation|
The Excavation: The most common problem
when excavating the area for your project is that most people dig to deep.
This causes two big problems, what to do with all the dirt you remove and
two, now you have to buy more base gravel to fill the deeper excavation.
The typical base for a walk or patio is from 4 to 6 inches of crushed gravel.
This of course can vary depending on each projects individual conditions
and circumstances, but still, most people will conclude that if they have
a 3 inch thick brick, 1 inch of leveling sand, and 6 inches of gravel, they
need to excavate 10 inches or more. This will place the top of the brick
even with the top of the ground.
This is good, right? Not really, the project will have settling. Ever notice that the ground around your driveway or walk seems to get higher every year? What is really happening is that your drive is sinking. Each spring, the ground under your drive or walk gets super saturated with water. This liquefies the ground and with the weight of the drive above pushing down, forces the ground to ooze out from under your drive. This settling can range from no movement to 1/8” of an inch each year (depending on the soil conditions and amount of water). If we install our patio so that it is even with the surrounding ground, it is possible that in a few years it will have settled below ground level and now, each time it rains, it holds water and has dirt washing on to it. To solve this problem, we raise the brick higher than the surrounding ground, reducing the amount of dirt we need to excavate and allowing for settling.
The following guidelines should be considered when excavating for your project:
- Try to remove all lose soil,
- Excavate to undisturbed soil,
- Never replace removed soil (it will settle),
- Excavate six inches farther then the end of your patio (edges always
settle, by extending the base farther, you reduce the chance that the
edge of the patio will collapse downward).
|Spending a little extra
time by installling 2x4 screed-rails will make it easier to level
and give you a much more level project.
The Base: Now that
we have the area excavated, it is time to prepare the area for the gravel
base. The simplest method is to place screed-rails on each side of your
work space. These are used to smooth out and level your leveling sand. Straight
2x4s on edge can be used for this. They are placed on the outside of the
work area with the top of the 2x4 set to the pitch and height of where you
want the top of your patio or walk. They should run parallel to each other.
These will be removed after the brick are installed.
A third 2x4 will be used as a screed-bar. This will also need to be straight and be long enough to sit on top both screed-rails when placed perpendicular to them. Lastly, a fourth 2x4 will be striped to the thickness of the brick that you will be installing and cut to fit in between the screed-rails. This will be attached to the bottom of the screed-bar and used for leveling.
When the screed-rails are firmly installed, it is time to start filling the excavation with the crushed gravel. The gravel should be placed in the excavation in layers that are about 1 to 1½” inches thick and then compacted. All too often, the excavation is filled and when compacted only the top is firm, the gravel underneath is still loose, allowing for settling. It is very important that all of the base is compacted. Installing the gravel in layers and compacting each layer will ensure a solid base with complete compaction.
For small projects, the gravel can be compacted with a hand-tamper, but for larger projects it is recommended to rent a plate compactor. If the crushed gravel is dry, dampening the gravel with a garden hose will also help it compaction. Don’t add to much water, just dampen the gravel.
Add the gravel and then compact each layer until you get near the top of your excavation. When sliding the screed-bar across the rails, you should have about a half-inch gap between the screed-bar and gravel. If the gap is bigger, add more gravel and compact again. If the gravel touches the screed-bar, remove some gravel and compact again.
When the crushed gravel is firm and to the correct height, it is time for the leveling sand. Contractors like to use torpedo sand for leveling. When the sand is in, they will take their plate compactor and force the brick into the sand by running the plate compactor over the top of the brick. This is not advised for the homeowner. It is too easy to scuff the face of the brick and ruin its finish. Rather, for the homeowner, we recommend using limestone screenings, sometimes referred to as paver base. This is a crushed limestone that is screened to the size of sand. It is flakes of stone that interlock and provide a stronger and firmer surface to lay your brick on.
Place some screenings on top of the crushed gravel base. Working from one end, slide the screed-bar from left to right while pulling it forward. This will level and smooth the limestone screenings. This should leave you about a half-inch layer of screenings over your crushed gravel base. Now, compact the screenings. Again, add some more screenings and screed them smooth. Compact again. Repeat this procedure until the screenings is firm, level and you have no gaps under the screed-bar when it is slid across the rails.