Just knowing something about a contractor isn’t enough. In order to ensure a quality installation, you should ask questions of the contractor such as:
With answers for these questions and others you might have, plus answers on how to know when the installation is being done right, you should be able to select a competent contractor.
I have created this chart for you to use while evaluating contractors.
This is something I would like to share with everybody, especially the home owners, because I see many failures of pavers jobs. It is not the pavers fault, well installed pavers systems don’t fail, 99.9% of the times is installation problems or negligence, like base installation or compaction issues.
What is interlocking?
In short, it’s the inability of a paver to move independently of its neighbors. It’s the locking of the pavers that causes loads to be spread over a wider area of pavers than where the load was applied. It’s the key to the strength of the pavement system.
Any interlocking patio, sidewalk, pool deck, etc. is a system, for the system to work properly we need to have all the components. The components include a base, bedding sand, concrete pavers with sand in their joints, and an edge restraint to contain the pavers at the perimeter.
This is the most important and is what you DON’T see, the base is typically made of compacted, crushed stone that varies in size from one inch (25 mm) down to dust. Base materials used under asphalt street pavements are acceptable for use with interlocking concrete pavements, the minimum base for any system here in the northeast should be no less than 4″ thick. Another important aspect is COMPACTION, the base must be mechanically compacted by a plate tamper or roller.
Bedding sand under any interlocking paving system should conform to ASTM C 33. This material is often called concrete sand. Masonry sand should never be used for bedding, nor limestone or stone dust (these materials create problems with compaction, lateral drainage and efflorescence).
There is a wide variety of shapes and colors, finishes and there is many installation patterns. However is always better follow a pattern in which the pavers interlocks themselves.
Edge restraint.
To avoid tipping or movement of the edge pavers is neccesary install a edge restraint, this can be made of recycled plastic or cement. Is very important to install the edge below the finish grade. Once the edge is installed, If you can see it is WRONG and is not going to work, especially in the winter.
In the joints between pavers is important to install a good polymeric sand (sand with special polymeric additives which hardens in contact with water) so no weeds or insects can get in the joints. In some cases (like my own back sidewalk) over the winter the ground hives and some of the sand looses, so every other spring when everything goes back in place, the sidewalk needs couple of handfuls of sand. And that is the only maintenance a well installed interlocking system needs.