ICPI Consumer Guide to Interlocking Concrete Pavement Installation and Contractors

How to know when the installation is being done right.

As a conscientious owner, you want assurance that the contractor you hire will do a quality job. Asking questions can help. Several are listed below for your convenience. It is important that you take time to ask questions about all aspects of your project with a qualified contractor.

Will the excavated area be a minimum of 6" (150 mm) wider than the actual paved area?
Answer: Yes, when the aggregate base is placed in the excavated area, the extra width will help ensure stability of the base at the edges, and provide space for the required edge restraints.

How will the contractor grade the paver installation for drainage?
Answer: By sloping the paved area away from the house at a minimum of 2%.

Will the aggregate base absorb or hold water?
Answer: No, when compacted properly, its density will minimize deformation and/or heaving of the paved surface during freezing or thawing.

Will the base be aggregate, ranging in size from approximately 3/4" (20 mm) to sand?
Answer: Yes, this facilitates compaction to a required density while allowing proper water drainage.

How will the aggregate base be compacted?
Answer: In 4" (200 mm) layers to achieve the maximum density and load bearing capacity. Each layer will require several passes of a compactor to achieve this.

Will the bedding sand be loosely screeded to a depth of 1" (25 mm), but no thicker than 1 1/2" (40 mm) thick?
Answer: Yes, the loosely placed, even layer of washed, coarse sand provides a setting bed for the pavers. When the pavers are placed on the sand and compacted, the sand moves up into the joints. This causes the pavers to interlock and become level after compaction. Note: limestone screenings and stone dust should not be used for bedding sand.

How will the contractor assure an even color mix of the pavers?
Answer: By taking pavers from several bundles or pallets at a time.

Will an edge restraint be installed?
Answer: Yes, an edge restraint around the perimeter of the pavers is essential for eliminating horizontal creeping of the pavers and loss of bedding sand.

Are the joints filled between the pavers?
Answer: Yes, with clean, fine sand. The sand should be dry sand so it will flow freely into the joints. The pavers are compacted during and after filling to begin interlock of the units and prevent sand from washing from the joints.

Should there be inspection of the pavers after their compaction?
Answer: Yes, the owner and the contractor should inspect the pavement together and confirm the owner's satisfaction.

Do I need to seal the pavers?
Answer: No, pavers are extremely durable. Sealing, however, may enhance the colors and may prevent staining. Allow a minimum of 60-90 days after completion of the installation before sealing. Consult your supplier for recommendations on cleaning and sealing.

Interlocking concrete pavers create a beautiful and durable pavement which should last a minimum of 30 years when installed correctly. Other pavements such as asphalt or poured concrete experience a shorter life. A well-designed and durable project can depend on you taking a little extra time making the right decisions to get the best possible results.

Knowing your contractor

Just knowing something about a contractor isn't enough. In order to ensure a quality installation, you should ask questions of the contractor like:

• How long have they been installing pavers?
• Have they been trained by a manufacturer or by the ICPI? Do they have written certificate of completion?
• What percentage of their total business consists installing concrete pavers?
• Will they provide you with three references, not only recent ones, but from past jobs?
• Can you contact their references and inspect the jobs?
• Do they have a portfolio of photos and letters to qualify themselves?
• Are they in good credit standing?
• Do they have a current liability insurance certificate? While the contractor is on your property, they should be insured for any damage and injuries that may occur. Check your homeowner's insurance policy for coverage of the contractor while on your property.
• Can the contractor provide proof that Worker Compensation insurance covers all on the job?
• Do they install the job per ICPI specifications? Can they supply a copy?
• Do they provide a written, itemized proposal outlining the scope of work and terms of payment? It should include starting and completion dates, demolition and excavation, paving and base materials, and taxes.
• Do they guarantee their work for one year? Will they return in a year to inspect it?
• Are they members of the ICPI or other associations?

With answers to 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.

Be sure to contact your supplier or the ICPI regarding proper installation of the particular paving products you have selected. Ask your contractor if these procedures will be followed. If you are a do-it-yourselfer, make sure that you contact your supplier for detailed installation instructions.

With all these specific questions answered, you may still have some general questions. The following are some of the most common questions with answers.

General Notes/Questions

How long do concrete pavers last? 30 years which is much longer than other pavements under normal residential use.

Can dirty or broken pavers be replaced? Yes, you can be assured of replacement pavers by keeping extras from the job. When replacing a paver, scrape out the sand in the joints from those surrounding the paver to be removed. Use two screwdrivers to wiggle it out. Others can be removed by hand. Insert the new paver, replace the joint sand, compacting the paver into place with a rubber mallet.

Will freezing and thawing damage pavers? No, damage from ice is virtually non-existent. The joints allow the pavers to move without cracking in freeze and thaw cycles.

If pavers need to be removed for below grade repairs, can I replace them afterwards? Yes, unlike other pavements, concrete pavers can be easily removed and reinstated without any visual or functional changes.

Will pavers be slippery? No, their surface texture is ideal for obtaining safe traction in pedestrian, vehicular, and pool applications, even when wet.

Additional questions you may have can be answered by a manufacturer's representative, a contractor, or the Interlocking Concrete Pavement Institute (www.icpi.org).

Your concrete paver project is just like any other home improvement. Do your homework, and reap the rewards for years to come. Enjoy!

The ICPI wishes to thank the Ontario Pavingstone Manufacturers for the use of this brochure. This brochure is intended to be used as a general guide for the installation of interlocking concrete pavers. The materials and construction methods may vary as a result of diverse conditions in every region.