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Paving
Brick installation
Process
Paving Brick Basics
There are two types of
installations; vehicle traffic and non-vehicle traffic. The
installation process is very similar for both types. We will cover
both in these instructions. You will first need to understand the
materials and amounts needed before work can begin. Paving brick is
installed in layers.
- Base Stone - is the
layer that provides the strength and flatness of the paving brick
surface. Spend lots of time on this layer, it will pay dividends
later in the installation process. We recommend you use a stone
product called 'Crusher run'. It is crushed limestone blended with
decreasing sizes of limestone. This product has sharp angular
edges that compacts well. The size of crusher run will depend on
how much weight the surface is to bear. Most side walks and patios
require 5/8 inch crusher run, also referred to as 'Driveway mix'.
Driveways will require 2" Crusher run. Your
excavation depths will depend on soil type and whether the paving
brick project is for vehicle traffic or non-vehicle traffic.
Assuming you have good sub-soil, projects for non-vehicle traffic
will require between 4 to 6 inches of base stone for vehicle
traffic, you will need between 8 to 15 inches of base stone. Again,
there is a big variation of the depth of base stone because there
are many factors that have to be examined to determine how much
you will need.
- Bedding Sand - The sand performs
two important functions. The first is that it provides a cushion
for the paving brick. The second is that it holds the brick joint sand from
washing out. This is the least expensive part of the whole
installation and it causes so much trouble when the wrong sand or too much sand is used. It doesn't matter whether your
project is for non-vehicle traffic or not, you will want to screed
a uniform 1 inch layer of sand over the stone base. This layer
does not get compacted until after the brick is placed over it. As
mentioned before, the type of sand is very important. Do not use
play sand, mason sand, or sand box sand. The sand must have the
same properties as the stone base, sharp angular edges and
decreasing smaller particle sizes. The top particle size is rather
large, about 1/8 inch in diameter. The reason is that you want the
sand base to compress uniformly across the entire surface area.
The use of other sand material does not compress uniformly and
will cause a wavy surface in time. The sand bed is the weakest
layer in the whole installation and the deeper you go with sand
the weaker that layer becomes. Edge restraints are designed
for a sand depth of 1 inch.
- Paving Brick - This layer
is pretty simple but there are a few things to mention about the
brick layer. Standard pavers are ( 2 3/8" ) 60 mm thick. This
is suitable for sidewalks, driveways, and light use parking lots.
Most paving brick styles now have joint spacers on the sides. Place the brick tight together and it will leave a sand joint of
about 1/16 inch.
- Edge Restraint - The use
of a good commercial edge restraint is critical to a strong and
long lasting paving brick project. The edge restraint gets
installed around the perimeter of the brick area that does not
butt up against a hard surface such as a driveway, sidewalk, or
foundation. The job of the edge restraint is to keep the brick
from moving laterally and having the brick joints spread apart.
When this happens, the interlock fails and the whole surface area
starts to fail. The edge restraint gets installed directly on the
stone base. Pull away any excess bedding sand before installing
the edge restraint. Drive in anchor pins a minimum of 1 foot
apart to anchor the edge restraint. Remember, these commercial edge
restraints are designed to be invisible, meaning you will back
fill over them with top soil or mulch to hide it.
- Sand Joint - The kind of
sand you use for the joints will determine how well you will
create the lock-up and how much time and labor goes into filling
the joints completely. Joints that are not completely filled not
only are the cause of a weak lock-up but also the reason grass or
weeds infiltrate the sand joints. Stores that sell paving brick
also carry bagged dry joint sand. If the sand is wet, you can not
work it into the joints and it takes much longer to fill all the
joints.
Steps to Installing Pavers
1) Excavation
Before you put a shovel into the
ground, you should check for underground utilities. You must excavate a minimum of 6
inches. Excavate 1 foot when possible, beyond the finished edge of your brick area on all sides that
do not butt up against hard surfaces, such as; asphalt, concrete, or
foundations. This is done to allow for the edge restraint
to be installed later. When digging, do not dig deeper than
necessary. Your goal is to leave the sub-base untouched. If you do disturb
the sub-base, run a plate tamper over it before filling with the
stone. Your excavation depth will depend on what type of paving brick
project you are building. For
non-vehicle surfaces, allow 4 inches for the stone base, 1 inch for
the sand bed, 2 3/8 inches for your pavers that equals 7 3/8 inches
deep. Your sand bed will compress about 1/4 to 5/16 inches after
compaction so you will want to dig about 7 1/4 inches deep.
2) Base Installation
Place the crusher run stone and
compact in layers no more than 4 inches deep. The stone base is the
layer that determines the contour and slope of the paving brick
surface. You do not use the sand bed to determine the grade or slope.
The sand bed and pavers will follow the contour that you create in the
base. If your base stone surface has valleys and high spots, these will
show up later in the brick surface. Allow 1/8 to 1/4 inch slope per foot for
drainage. Make sure that you compact the stone base thoroughly, paying
special attention to the outside edges. A poorly compacted base will
allow the pavers to move and settle. Do not rush through the base
installation. This is the foundation of your paving brick surface and
the time spent here will reward you with a quality installation.
3) Bedding Sand
The bedding sand gets screeded in a
layer 1 inch deep. To achieve this, use two pipes that measure 1 inch
in outside diameter. I like to use black iron pipe for this, it is rigid
and inexpensive to buy at your local hardware store. Lay the two pipes
parallel to each other and place bedding sand across them, then pull a
straight 2 x 4 across the top of the pipes. You do not need to screed
the whole paver area before placing bricks, you can screed in
sections. It is best to keep the moisture in the sand by covering your
sand pile with a tarp or plastic sheeting when it is delivered to you.
If your sand dries out, you can spray it with a garden hose to
remoisten it. The bedding sand will get compacted in the last step of
installation. Do not walk on the sand bed. After you have
screeded across the pipes, lift the pipes out of the sand bed and fill
in the groove left by the pipes and smooth over with a cement trowel.
Make sure to screed out beyond the finish edge of where the brick will
end.
4) Placing Paving Bricks
Stretch a mason line or snap a chalk line in the sand
bed to start from. Place the pavers along this
starting line in the pattern that you choose. Set the pavers on the
sand, but don't hammer them into place. There should be a slight gap
between the pavers. As you work, stay on top of the pavers, not on the
sand. Every 2 or 3 feet, set a string line and check both line and
alignment as you go. Use a rubber mallet or dead-blow hammer to adjust
the alignment. When you can't place a paver because it needs to be
cut, leave it out, only place full pavers for now. After placing all
the pavers make the cuts and place them. Now inspect the entire
surface for chipped or defective pavers and replace any that you find.
Check your lines and adjust using your mallet or a large screw
driver.
5) Installing Edge Restraints
Use a square point shovel or cement
trowel to cut down along the outside edge of the pavers down to the
stone base and pull away the excess sand away from the pavers. Being
careful not to cut into the stone base. After you have removed the
excess sand, place the edge restraint up against the pavers, right on
top of the stone base. Drive the anchor pins in 1 foot apart for
non-vehicle surfaces and 6 to 8 inches apart for vehicle
traffic.
6) Compacting Pavers & Sanding
Joints
There are two methods to compacting
and sanding that you can use. The first one is to spread dry joint
sand over the surface and sweep in to fill the joints. Then run the
plate compactor over the paver surface first in one direction then perpendicular
to the first one. Run the plate tamper over the surface until you have
filled the brick joints completely to the top. Wet sand will not
vibrate into the joints so make sure the brick surface is dry before
attempting to place sand. The other method is to run the plate tamper
over the surface before sanding the joints. After running the plate
tamper over the surface in two directions, sweep the joint sand into
the joints. Run the plate tamper over the surface again. I like to
use this method because it does a better job of leveling the brick
surface and I also feel it does a better job of locking up the pavers.
When you are done compacting, sweep off the excess sand, I like to
leave a little sand on the surface to let Mother Nature work in any
places that I have missed. You can also mist the surface with a light
spray from your garden hose. The goal is to completely fill the sand
joints to the top, this is important to the strength of the project
and to keeping your brick joints weed free. After the first winter you
will find the the sand joints have settled, all you have to do is
sweep in more joint sand to fill them back up to the top.
7) Clean Up & Final Inspection
Inspect the surface for bricks that
might have been chipped or cracked in the compacting step. If you find
any, replace with good ones and re-sand. Back-fill over the
edge restraint with soil or mulch. The last thing to do now is sit
back and admire your work. Back
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